I imported a level 15-17(ECLs) party with the end-game equipment(my actual party was level 20-22, and I thought that was overpowered for HoF). They are doing alright. The enemies do hit, but a Barbarian with 400HP just shrugs the damage off with a rage that carries him to 460HP, the Paladin heals it, the Monk evades it blinking out of existence, the Ranger may eat it up, and then kill off the little thing with his 30 STR dual scimitars, the rogue backstabs the man before he even makes a move(on average 50-80 backstab!) and the fighter... actually, the fighter is the one who I have to get out of situations, as she gets to low HP soon, and doesn't have the cool class specials of the other partymembers. But she can still deal alot of damage with her Bastard Sword of Chaos(partly the reason of her dangerous situations, berserker lol) or any other(rare) good bastard sword. Two of my partymembers are totally immune to spells, the Svirfneblin Monk with 50, and the Drow Paladin with 45 Spell Resistance. It was kinda cool to watch them carry on the fight while everyone else is paralyzed.
This party is a power experiment, and I powergamed the hell out of it. I don't really like powergaming much(detest it actually) but this was fun! Several of the fights in HoF I literally watched through, the marauders just cleaving through the enemy