I tried them only when I played ToEE for the first few times and had no idea what RPG even means. Never finished those runs due to lack of game understanding at that time. Their stats are so horrible, I think it's almost impossible to make PCs worse than pre-generated ones (unless if you're role-playing iron mode and getting super unlucky). Though it's not that challenging to complete a run using them if you're an experinced ToEE player.
Thanks. That was my impression when I was playing the game but thought I would ask others their opinions.
I used the pregenerated character for my first playthrough. My party consisted was neutral good and consisted of Alhandra(paladin), Regdar(fighter), Lidda(rogue), Eberk(cleric), and Aramil(sorcerer). I found the Lidda to be the worst of the bunch. I didn't need her thief skills and I made the mistake of having her use crossbows. Everyone was pretty useful in their roles.
I think it depends a bit on how familiar you are with D&D and TOEE. The regenerated characters look to be point buy 25, with quite few having 15,14,13,12,10,8 arrange as desired stats that I think was designated the 'elite array', which while not spectacular is pretty solid. Assignment of stats is sometimes pretty poor: Naull looks like a pretty solid wizard with the elite array, while Mialee has better numbers but poor placement (CON is never a good choice for your dumpstat, and both of these waste their first feat on Toughness). The other issue is some poor choices of starting feats: Lidda has Dex 19 and Str 8, so while Improved Initiative is not bad generally, Weapon Finesse or Point Blank Shot would be much better. Kerwyn wastes both feats on skill boosts. Regdar's Weapon Focus: Great axe is suboptimal. Eberk has poor stats but probably the two most useful domain choices (Good gives you holy smite and the ability to craft holy weapons, while Earth boosts a Clericzilla further with Stones kin and Spike Stones). Jozan has better stat allocation but would be better with the Sun domain than Protection. Still, I think with a degree of metagame knowledge (which I think is reasonable to assume 20 years on from release and 10 from the last CO8 Modpack), I think that one could succeed in completing both the original content and the new content with a party of pregen characters. Temple+ makes it easier (Lidda takes swashbuckler as her second level, for example). It depends too on how many and which NPCs you recruit: Elmo makes it a whole lot easier to stay alive while you acquire the levels to correct some starting weaknesses, Melany is always a good addition because a druid is always worth having, plus holy longsword. Spugnoir is a pretty good wizard option. You'd probably waste a bit more XP on stat boosting items earlier than with a bespoke party. I have done one NPC (bard) + Hommlet residents, and it was pretty good. My first playthrough way back was with PCs I'd rolled myself, with little knowledge of D&D 3.5 (I'd played a lot of 2ed ten years previously) so some of my choices were sub-optimal: I saw Power Attack as a trap rather than a feat tax to acquire Cleave, and didn't really make use of my rogue's sneak attack at all, but I still made it to the end (Sword & Board paladin, TWF ranger, Cleric of Pelor, Wizard, Rogue who eventually took a wizard level and used wands as secondary artillery).
Game familiarity and system familiarity trumps all (as far as difficulty); with metagaming and a good grasp of how TOEE's implementation of 3.5e (especially crowd control spellcasting) works, it's not that difficult to dominate even with subpar builds once you get past level 3 or so, especially if playing with Temple+ options. Throw in the expanded crafting options and the fact the enemies for the most part lack sophisticated tactical options (especially good spellcasting support), about 90% of the base/vanilla content can become a cakewalk by midlevels if you're familiar with the game. Often my biggest challenge with TOEE is boredom by mid/midhigh levels due to lack of challenge preVerbobonc... which results in endless restart-itus with lvl 1 parties, each time trying different challenges/handicaps to make the game more interesting. I've yet to try a completely pregen character party admittedly; maybe it's time to give this a try.