They are both excellent companies with excellent products. The BAT's you are interested in are quite a bit more expensive than the arc's you compare them to: $16,000 vs $11000. I think the BAT SE equipment is more transparent, but ARC equipment seems to have a fuller body and sense of power. Speaking of, the vt100 has 100w vs the bat at 75w. I know my vt100 has been able all my speakers quite well. Excellent dynamic drive for a tube amp.
I think the BAT SE preamps are much better than the ARC's. I have not heard the new ls25m2 though.
I'm running a vt100m2 with a bat vk-5i to great result. I'm going to put some NOS tubes in it and see if that improves things further. I put some svetlana kt88's in the vt100 and they give it a little more transparent midrange and warmth.
I think the BAT SE preamps are much better than the ARC's. I have not heard the new ls25m2 though.
I'm running a vt100m2 with a bat vk-5i to great result. I'm going to put some NOS tubes in it and see if that improves things further. I put some svetlana kt88's in the vt100 and they give it a little more transparent midrange and warmth.