I have been running two of my friends through a campaign. I would say it's average to high magic level. In fact, it's a modified version of the Rise of the Runelords. One of the party members is a rogue and is totally in love with the +1 returning cold iron dagger he got for killing the quasit in the Catacombs of Wrath. Both players have been facilitating the absence of a full party with NPCs they've met along the way. They are level 5.
Another buddy of mine has always wanted to join us but his schedule always conflicted. But coming up next weekend he's free so I'm setting up an epic marathon game session for all of us.
Here's where I need advice: He rolled up a fighter. He's specializing in a greatsword (he wants the chance to cut enemies in half). I had him roll stats exactly how all the other characters rolled stats; 4d6, eject lowest die, roll 8 times, eject two lowest rolls. I kick myself for not using a 15-point buy, but what's done is done. The first two players rolled decent stats, nothing crazy so I dodged a bullet. Now comes my fighter friend. He rolled hot. 16, 16, 15, 15, 14, 13, 11, 9. That's stupid good and I immediately worried that after he got rid of his two lowest rolls he would steamroll past the other players.
So I made a deal with the devil. I told him that if he took the 9 and the 11 instead of the 14 and 13 I would let him have a +1 greatsword with one +1 special ability. Ug, then I started looking over the special abilities and some of them are highly situational, requiring you to have certain abilities, but others are like holy crap, that's powerful! Let's be honest, a +1 returning dagger shouldn't be roughly considered the same power level as a +1 holy greatsword! They both have the same number of enhancements.
Now I'm worried the other players are going to look at the fighter as getting a big hook-up, showing up with a flaming sword.
Knowing all of this, what would a good DM do? Let him keep the stats? Trade them for a sword? Something else?