6505+ thats the amp .....Ive had all the amps you mentioned. If you want the Killswitch Engage type of tone that is it, all you need is a good overdrive infront such as a Maxon 808. Dont believe what someone said about falling apart at high volume. The peavey slays at high volume in a live mix, that guy must have had bad tubes or something wrong with his amp. I use mine in a two guitar band and the more I turn up the better it sounds not the other way around.
Soldano , I have ownrd SLO , HotRod 100 and an Avenger 50. Out of those three the Avenger did Metal the best but it had no clean channel and no loop.
Splawn Ive had Nitro and Quickrod , cool amps but like you are right.. if you want saturation and fast attack you would be better with a 5150/EVH/Soldano type amp.