Ok,
I had my first game last night with a summoner (QOshea from these boards).
Summoner : Level 9 Dragonwrought Kobold (green)
Summon : Medium Sized Quad with Wings, Bite, Claws, Elemental Attack (Acid), improved natural armor, and improved Con (I believe this is accurate).
The rest of the part :
Half-Dragon Cleric/Paladin of Bahamut (Bronze).
Half-Dragon Ranger (Cohort of Paladin).
Half-Ogre Knight.
Woodling Catfolk Druid.
Advanced HD Grimalken (Druid Cohort).
Duerger Duskblade.
Drow sorcerer/ranger/arcane archer.
The paladin & Druid are 8th class level, but all characters are 9th level total.
Roleplay : The summoner had all sorts of trouble with his summon, it looked like a green dragon, while he looked like some sort of wierd green lizardfolk (to the people they were around). The summon was nearly attacked by arrows and guards several times, and he ended up either having to dismiss it or leave it outside the city (and take hte hit point loss) due to it's form. This seemed a decent cost for a big nasty acid spitting summon with wings. Since the creature could take any form he wanted, he had it take the form of a medium sized green dragon complete with military saddle and bridle so he could ride it. Since there is no rule against summoning it with 'built in' equipment, I didn't see a problem with this, and it neatly bypasses the issue of summon mounts and equipment. If the rules on it change (which I hope they do, I don't see any issue with the summons taking equipment with them when they go away), I'll revisit this, but it doesn't seem overpowering either way.
Combat : They ended up traveling through a swamp and getting ambushed by 3 blue spawn gators (gators with dragon blood, blue), and a greater blue spawn gator. These are all GM Custom critters, obviously, but I'll put the stats below :
Blue Spawn Gator
STR : 25 DEX : 18 CON : 22
INT : 2 WIS : 14 CHA : 10
Size : Large
AC : 20 : 10 + 4 Dex - 2 size + 8 NA
Bite : +15 1d8+7
Claws : +15 1d6+7 x2
Pounce, Improved Bull Rush
Breath Weapon : 60ft line Lightning (6d6), once per day
Move : 40ft, swim 40ft
HitPoints : 150
Greater Blue Spawn Gator
STR : 30 DEX : 16 CON : 24
INT : 14 WIS : 14 CHA : 12
Size : Huge
AC : 25 : 10 + 3 Dex - 4 size + 14 NA
Bite : +18 3d6+10
Claws : +18 1d8+10 x2
Pounce, Improved Bull Rush, Diehard, Endurance, Improved Natural Attack (Bite), Fleet, Fleet
Breath Weapon : 120ft line Lightning (10d6), 1d4 rounds
Move : 50ft, swim 50ft
HitPoints : 300
The group was trudging through the swamp, the paladin was using his wings for short flights, while the rest were mounted on either horses or riding lizards (75hp cr 5 lizards with swim speed). The summoner was flying overhead making figure 8's over the party. The druid was riding her grimalkin cohort (who had taken the form of a large tiger).
The blue spawn initiated combat and attacked in the surprise round. They adjusted as able and fired their breath weapons to hit as many people as possible at once. The knight went down when his horse got blasted into nothingness (magical horse, it disappears when killed), the arcane archer had a real horse that got turned into meat confetti when the first breath weapon did twice it's hitpoints and it exploded between his legs. The paladin was immune to electricity, and weathered 3 breath weapons without damage. The druid and grimalken took two hits, saving for partial damage on the huge one, and took full on the large one.
The knight reconstituted his horse (magic horse) just in time for it to get blasted a second time by the last large blue, so he lost his first turn. The duskblade attacked large blue #1 and whiffed, the paladin cast ring of blades, the grimalkin attacked large #3, and the druid dismounted and became a large tiger also, so large #3 was getting dual mauled by large tigers.
The summon did a flyby on #1 arially and clawed it. Summoner used his SLA to pop a grizzly bear next to the two tigers (next round). The ranger whiffed against #3, and the arcane Archer whiffed against #2.
End of Surprise Round.
Round 2
Grimalken and Druid maul #3, #3 mauls Grimalken. Summon does a flyby attack on #2, while summoner uses his lance to attack as well. The two do a good bit of damage to #2. Grizzly bear appears and mauls #3 (nearly dead). #3 attempts to run, and 3 AoO's more than kill it (all 3 hit).
#2 charges the Arcane Archer, does a bite/claw/claw pounce and leaves him at -7 hp. Duskblade and #1 trade attacks, Duskblade crits his second attack (first missed) and he does almost (but not quite) half the creature's hp's in one hit. Paladin charges up to Huge Blue and huge blue AoO's him (10 foot reach). Both do attacks against each other, and the huge takes almost as much damage from the ring of blades as he does (bad rolls for his damage, good for paladin's ring of blades). Knight brings his horse back and mounts, moving it 15 feet sideways to prepare for a charge next round.
Round 3
Bear charges #2, mauls it. Grimalken charges #2, mauls it. Summoner and Summon fly-by #2, do good damage as well. #2 over 100 hps taken. #1 fails it's will save and runs away after being critted by the duskblade last round. AoO does a few hps, but nothing major. Duskblade Acid-Orbs #2 this round, adding to the damage. Druid races over and avoids an AoO from #2 to cast cure Moderate on Arcane Archer (who's still in #2's mouth). Archer wakes up to realize he's still in #2's mouth. #2, having food in mouth and being badly wounded races off with archer in mouth. Archer takes 13 more hps and drops unconscious again. Knight charges Huge blue and shatters his lance in it's side, doing a nasty hit. Huge blue withdraws and then runs away as well, having seen his pack run away, and having taken over 100hps in 2 rounds with little to show for it. Summon and summoner race after #2, shoot it with a bow, but miss.
Round 4
Duskblade fires another acid blob at #2 from afar and hits, taking it down (it was at 0 hp's anyway thanks to acid from last round). Paladin has to lift blue off of archer, summoner digs him out of mud, and druid arrives on the wing to cast cure moderate again. Everyone survives. Bear disappears later.
All in all, the summoner was able to contribute nicely. Granted, it was in the open in a swamp, so that played to the summoner's strengths given his summon. All in all, though, summoner wasn't too overpowered. Nor to underpowered. I don't think items on the summon would have made much difference, nor would the summon spell lasting 9 minutes instead of 9 rounds. I may have missed a few things in the combat, but I think I got the heart of it down.
Saves me the trouble of doing the report LOL.
The Duskblade used Acid Arrow, though. Still, the jerk took it down just before the Paladin and I would have been able to smack it!