I've never had an over the top rig, just the basics to do what I need. Playing in a 5 piece, medium volume classic rock band I've been using an Ampeg BA-210 with a PF-210 cab. Since I started using the MXR M80, if the PA has subs I'll only use the BA-210 so I can hear myself (and DI through the PA). Like most of us, looking to expand our range and tone I was wondering if I should look for a head to use with the PF-210 and have that as an option. I've always thought the Micro SVT stack was a cool idea, but not sure if it would be any different than the BA-210 (micro SVT comes in 100w, or 200w vs. 283w on the 210). Adding a head to the Porta Flex would provide some latitude in tones and wattage depending on the head (plus a chance to use the flip top). I won't lie, there is something about the Ampeg tone...
Just thinking out loud here...
The Ampeg micro-stack, comes, as you mentioned, in two flavors: the
micro CL and the micro VR. The VR head is 200 Watts (@ 4 Ohms -- 150 W @ 8 Ohms) and the VR stack comes with an SVT 210 AV, which is a legit -- if compact and medium-duty -- cab (also rated for 200 Watts). The CL head is 100 Watts and the cab (MC 210E -- only sold with the CL head) is likewise rated for 100 Watts.
I've only noodled around on the CL stack once, that I recall, in a store. I've played through the VR stack (with one and with two of the 210 AV cabs) on stage a few times.
I would not be confident playing the CL stack in many live settings with the sort of band you describe
AND (I could be wrong about this), I don't think that the CL head will drive a 4 Ohm load (which would mean no hooking up two cabs), which would make it a hard no for me.
The VR head with one 210 AV sounded really nice -- appropriate tone and more-or-less pocketed itself into the mix -- with a four string bass at a medium-level pub jam. Managed to carry the small room until the drummer started to open up, then it struggled (especially with the house bassist's five string -- whose rig it was). Same rig, same place, with a second 210 AV cab (skinny stack) did much better -- sound was more full and dynamic, easier -- but it's still a medium-duty 410 (and wouldn't be my first choice with a 5 string).
...My thoughts were that a lighter rig would be nice, which segued to the Micro. I saw a used one last time I was in one of our local shops at a good price, it was the 100w version. Just wondering if it would have enough volume on stage, our keyboard player has a Leslie cab that is pretty loud. My 210 is just loud enough by itself on stage, which was where the thought about finding a more powerful head for the PF 210 cab. The PF with a head will probably weigh in about the same as the BA210.
Neither micro 210 stack is going to match your
BA 210 combo or your
Portaflex 210 (if adequately powered) for volume. (Especially not the CL head or its associated cab -- not even close -- nor would I hold out much hope for it keeping up with a Leslie.)
If you dig the Ampeg sound, you could mount a PF-500
or, if you're careful, a PF-800 in your 210 HE cab, sell your combo, and add a second of the same cab (if you ever need it for louder stuff). It'd be a better-matched and more potent setup than your combo + 210, but isn't exactly minimizing (in terms of setup or $$$).
Two of the 210 AV cabs, stacked vertically, have a tiny, tiny stage footprint. I would pair them with something like a PF-350 (or other, similarly rated head that you like). You might find yourself using two cabs more often than currently (I don't know) and you'd probably still want some PA support for bigger rooms or louder shows (especially if your keys player is channeling Jimmy Smith).
Other possibilites: You could look at 2x10 or 1x12 cabs that are more potent than the 210 AV (but still light weight -- depends on how much you dig your PF-210 and whether the lighter weight is worth it to you) and a more powerful amp OR (maybe counterintuitive), pair a powerful head with a lightweight, modern 2x12 (possibly in 4 Ohms). You'd lose the tiny-rig/modular option, but the right cab wouldn't be much more, in terms of size or schlep, than your combo or current cab, and would cover most things.
Off the top of my head, the Genzler Nu-Classic 212, GK Neo IV 212 (4 Ohm version), Mesa Subway 212 would all be worth a look (I'm sure I'm forgetting some) among current offerings. If you want to keep it Ampeg, the 212 AV is highly regarded (though a little heavier and wider-footprint).
Lots of ways you could go.
. But such is life, my BA's are both V2's with the wedge cab, even that won't push through when the Leslie is growling... Keyboard player is the BL, and an excellent player... and we've all overcompensated before... 
