I already have the Bogner Shiva EL34
I had my friend play all my rigs for me the other day exc for the 73 Marshall. I can honestly say the Bogner Shiva nails the Marshall tone all the way to pretty high gain JCM800. Doesn't get into the chunk chunk range so much.
I have played the Ecstasy Classic - and that amp does EVERY sound, BUT it's clean is more of a nice sparkly clean with great headroom and boost options. The Shiva has that ungodly clean that works for Jazz all the way thru R&B and country. It's as good as some of the vintage Fenders I have played - yeah, I said it!
I think the 6100 does a great clean - ask Johnny A - and has a gorgeous Ch 2. Ch3 is only good for single notes IMHO, kinda Mesa-ish. However, nothing sits in the mix better than a Bogner. Marshalls are nasty, but the Bogner is a bit sweeter and right where it needs to be.
I imagine the Splawn to be very rude and nasty and hige like my 73, but I have yet to hear it in person.