I bought the stock .500 S&W Katahdin Encore about a month ago and have been very pleased with it. I've put about 200 rounds through it thus far. It is a very lightweight rifle, as the 20 in barrel doesn't weight much with the half inch bore. My 28" .22LR Pro hunter barrel seems to weight about as much as the entire .500 rifle ready to fire. As such it packs quite a bit of kick, especially with full bore loads. Offhand it should make a great deer rifle, standing I've had no problem nailing the kill areas of the Visi-color Deer targets (1/3 size) at 50 yds, so that should translate to a 100yd+ rifle. Time at longer ranges will tell. The handling qualities are excellent with the short barrel and it should work great in the brush.
Mine also seems to prefer the 300gr Hornady bullets, although I've been using H110 and 2400 powders. I'll have to try some lilgun next.
I haven't shot much off the bench, as it seems to hurt more... The stock comes back hard and with little body movement absorbing the recoil, it dishes out bruises. Much better to stand up and let your body move with the recoil.
I switched out the stock peep sight insert with a .093 twilight insert and it works better for my eyes. I tried a .050 as well but it was too small.