Well, I have obtained one of these RedSub 5110 combos. I was waiting for the Thomann one to come back into stock but they kept pushing the date back repeatedly, then they delisted it (although they did say it would be back when quizzed).
Certainly it has no problem with practising - got aux in and headphones and sounds dandy at moderate volume levels.
I tried it in my wife's studio - it's separate from the house so I could crank it up a bit. I was rattling some pictures on the walls
So I took it to a band rehearsal last week, not convinced that it would be able to keep up with drums, guitar and keys. Well, it did. With gain set pretty high but without clipping and the master at about 1 o' clock it was easily audible and the band said they really liked how it sounded. Result!
I've got a jam round someone's house tomorrow night and I'm bringing it there. If it handled last week then I'm sure it'll be fine in this setting.
I did take the head out of the combo and hook it up to my Zoot 4x10 but it wasn't a very good test - too many rattly things in the room distracting me. Maybe I'll try it outside
So, the story will develop, but at this time you can put me down as surprised and impressed so far.
Obviously with it being something of the order of half the price of a Promethean something has to give - it's not the prettiest of boxes, the "stand" is a threaded post with a rubber foot that you screw into a hole in the bottom of the combo, the aux in and headphone sockets are 1/4" jacks which means looking for converters when the majority of things that you would plug in there (MP3 players, mobile phones) are 3.5mm jack. Removing the head is not tool free in my experience - the screws do have large slot heads with ridges for grip but they're just way too tight to turn by hand when fully screwed in. Maybe in time they'll free up a bit. Mine also smells a little funky after it's been on for a while - perhaps there's a daub of glue somewhere there shouldn't be. Again in time hopefully this will calm down. The DI is very basic, only a ground lift switch is provided (no pre/post EQ). But it's all little niggles which can be worked around/overlooked.
So basically, it sounds good, it's very portable, very flexible and while I'm sure the combo has its limitations in terms of bass projection (also don't put it up against a wall, it's rear ported), it has more than enough oomph to fill a rehearsal room with bass and given the choice between using this at a gig and not playing at all, I know what I'd do.