I have quite a large collection of tube amps. Off the top of my head I think the total is now 19. I don't own any sealed cabs and absolutely cannot stand the way the Ampeg 810E sounds. The lows are fine, but I do not like the high mids and treble response. Obviously millions of people love the Ampeg 810E so it has to be an awesome cab, right? Everyone should judge the cab for themselves; please don't let me personal opinion sway you.
I own several ported cabs and I would say amp cab/pairing is a significant factor in achieving the specific tone and feel you want. Just because you have an amp that you love and a cab that you love, does not guarantee they will work well together; this is especially true with tube amps due to their lower damping factor IMHO.
Here's an example. I have a pair of massive home built EV TL405 loaded with EVM18Bs that are setup in step down mode. Some of my tube amps sound fabulous through these cabs. In fact, I would say the TL405 is the best sounding cab in my collection for some of my amps.
But my Aguilar DB359 does not seem to get along with the TL405s very well, so I would say this amp/cab pairing is not a good choice. Basically the combination seems to produce a somewhat nasty low frequency resonance; if I remember correctly it's centered around G# on the E string; the tone is unusually loose, peaky, and uneven. To be honest many people would not even notice, but it drives me nuts.
I also own a bunch of Genz Benz GB1288Ts. The Aguilar DB359 sounds great through these cabs. My impression is the 1288Ts tuning is very well damped in the low end. None of my tube amps have any low frequency weirdness with these cabs. In fact the low end of these cabs is extremely consistent from amp to amp, which is not necessarily a good thing IMHO, because it sort of conceals or masks the individuality or uniqueness of each amp Consider how this relates to concept of the cab's quality of transparency. In other words the cab's ability to faithfully reproduce the subtle nuances in the signals fed to it.
The TL405s are truly enormous and totally impractical for gigging, but just purely on sound quality I would probably choose to use them with my SA200s over the GB1288Ts. The SA200s lows are fabulous through the TL405s, and I think the amps just sounds a bit more lively through these cabs overall than through the GB1288Ts.
Something to keep in mind is the SA200s unique tone control network. As long as a cab's sub bass response is even, rather than peaky, you may be able to get what you want out of the cab.
My impression is the SA200 is really setup to found fabulous with the tone controls set to 12:00. But here's the deal, the Bass, Mid, and Treble are laid out in the shape of what we lovingly call a Fender tone stack. The circuit has a Fat/Clean switch which changes the amps voicing and gain a bit. Also before the tone stack you have two additional tone controls circuits called Bottom and Top.
My impression is Bottom and Top loose effectiveness as you roll off the Bass and Treble controls--you might say the controls interact, or the Fender tone stack part of the circuit dominates the Bottom and Top controls.
Here's how this interaction is described in the owners manual:
Further, the relative level of the Bass control directly influences the effect the Bottom control has, and the relative level of the Treble...
The point is, as long as the cabs low end response is not peaky, you can pump up the lows with the Bass control and then roll back the sub bass with the Bottom control. IMHO the SA200s tone circuit is one of the best available in a tube amp.