I just went through a major project researching these, and bought and returned about everything there is from Guitar Center. I will give you my impressions. The Street cube series is okay but it really depends on what you play. If you are playing an electric guitar, you can get by with it. Lasts well on batteries, but has shallow bass If you play blues and are punching any bass these things are very week. I had a crate 50 watt. Battery life is not good, also when it starts to run down the bass starts to crackle - big 10" woofer. Also, it always runs off the battery, even if it is plugged in, so if it is not fully charged, it won't play even plugged in. I found it broke up quite a bit at any volume, but battery life was not enough anyway. Roland AC33 - very nice little unit, but expensive, but a real acoustic amp if you need one - runs on AA's, but drops to 20 watts on batteries. Very nice sound and has anti-feedback and looper - but again small speaker and if you need bass it does not cut it. Also tried expensive Roland PA's which do not cut it at all on batteries. If you do not need much battery life, there is a rechargeable PA by Samson that is very inexpensive the 40i I think it's called - 40 watts and very nice sound - big enough speaker to carry strong bass -- but battery life is probably no more than 90 minutes using an instrument and mic.
I settled on a Traynor TVM50 - 10" woofer, and true 2" tweeter. Great battery life, although it takes 24 hours to recharge you can use this on both channels for 6-8 hours at good volume. It is also made in England, so getting it in the EU should be no problem, and it was an economical solution here and probably cheaper there. Mostly, the only amp with decent woofer and enough battery life on a charge to cut it. It's 50 watts and has great volume and bass support. But if you are just playing electric and don't push the bass the Cubes are adequate. I don't know how they are with mics though. The Traynor is dual channel with 3 band EQ on the insrument channel and a "gain" button for pickups that don't have preamps, that's a big boost aside from the normal gain control.
The Traynor is comparable price wise too with the Street Cube; it is bigger and heavier but it depends on your needs.