As long as you run a fun game, why should your players complain?
Speaking as myself: I would not mind since I understand the time it takes for a high level build.
Speaking as my former self: The DM is cheating. Why can't he follow the same rules as us. etc, etc, etc.
PS:I used to have a DM who could get a game up in running in a very short amount of time. I am starting to think he did the same thing. When it was not me making high level characters I just didn't understand.
I do it all in a word processing program (Word Perfect for those interested).
One thing that this allows me to do is to have the stats for the creatures that are all the same, and where I have added a few lines with "O" for their each spell-like abilities, SU ones, etc. (with enough Os for each daily use) along with their individual hit points. I hand write in the identifier for the fig for that creature (blue, Raistlin, green, elf, etc).
This let's me know how many abilities have been used by which creature easily, and know if they died before they could use those abilities.
Spell lists (with DCs, durations, etc), once they are prepped, I use "strikeout" to mark off the cast pre-encounter spells (all day spells, etc.). In game, I simply strike off the spell as it is cast. Similar to the abilities, if I have several casters that are the same, they have their spells in listed with their abilities.
Example of Fudge:
My group is 15th level. I needed some tougher gibbering mouthers to throw at them. Here are the notes I wrote up in about 5 minutes, and was all I needed to run the encounter:
Advanced Gibbering Mouther CR 12
hp 160 AC 27 touch 15 flat 22 DR 10/bludgeon
Melee 6 bites +21 (2d8 plus grab)
Special Attacks blood drain, engulf (10d6 damage plus 2 Con damage, AC 22, hp 20), gibbering, ground manipulation, spittle (+6 ranged touch)
All-Around Vision (Ex) It cannot be flanked.
Amorphous (Ex) It is immune to precision damage.
Blood Drain (Ex) On a successful grapple check after grabbing, several of the creature’s mouths attach to its target. Each round it maintains its grapple, its mouths automatically deal 2d8 points of bite damage and 1d4 points of Constitution damage as it drains its victim’s blood.
Engulf (Ex) Medium or smaller.
Gibbering (Su) Free act: All within 60 ft DC 15 Will save or be confused for 1 round. A mind affecting compulsion insanity effect. +1 per gibber.
Spittle (Ex) Free act, one target 30 ft. +15 touch attack, blinded for 1d4 rounds unless DC 21 Fortitude save.
Note, to keep things fast I only used one gibbering save per PC with the DC increasing based on how many mouthers were within range.
Having run this encounter, if I were to do it over again I'd probably drop the hp in half to give them a more minion feel. But my group did a fine job chopping their way through them.