Hey Virgil,
As one who played an Ep amp for a while (502), I found the Epi EQ among the least powerful on the market. Compared to the EQ you are used to, the basic Puma EQ will be a revelation. Perfect control of deep bass (ability to cut or expand), low mids (nice ability to punch up the meat of your tone), upper mids (ability to smooth the gank or dial in the brightness) and treble (add or remove upper treble sizzle). The Puma's also have a voicing control (called 'Taste') that is similar to the Thunderfunk Timbre control or the Walter Woods 'balance' control.... revoicing the amp from 'dub' to 'mostly midrange' with one variable control.
While the Black Jag EQ adds what looks like some boost switches and some limited semi-parametric switches on the mids, I never felt I needed more EQ power with the standard Puma to match it to various cabs and deal with various room acoustics.
Assuming you don't need 2ohm operation (which the Jag can do with its dual power amps), a Puma900 through two 8ohm or a large 4ohm cabs is really something.
If you were cranking two 4ohm 410UL's with your Epi900, I guess you would miss some of that slam from that massive wattage. If you were, on the other hand, mostly using one side of that amp into a 4ohm 410UL (or whatever) I think you will find the Puma much more punchy, WAY more articulate, and much more even sounding set 'neutral' right out of the box.
The fact that it is a quarter of the size and weight would just be a bonus
FYI, I've been impressed with the new Glockenklang Blue Soul also... more than I originally thought I would. It has a bit more of that big, creamy low end of the Epi amps, but again, MUCH better control of the midrange. It slams HARD into a large 4ohm cab or two 8ohm cabs. FYI. The top end is REALLY clean and hi fi though, which might not be your thing. t