I've been using a Marshall AS50D for a few years and I love it. I've gigged it, spilled beer on it, dropped it, kicked it... Still sounds great.
For a small solo gig it eliminates the need for PA as you have mic and jack inputs ready to go and reverb/chorus which allow you to set the level for each channel. Phase and notch filter are great for cancelling feedback there are DI and line out from the back panel to go to a PA fo larger gigs.
I mostly play a Yamaha CPX500ii guitar through mine these days. I can't imagine needing to change it in the foreseeable future (unless it's to buy the larger Marshall AS100D combo!).
I've played uke through it, as well as mandolin (with pickups and through a mic). Also put vocals through it and played tin whistle and harmonica into the mic channel. All great.
The noise you mention is more likely to come from the pickup. After all, the combo just amplifies what the pickup detects. Perhaps you could EQ the worst of it out. In fact, different EQ settings may well be the reason for the difference you perceived in the amps.
The little Rolands are neat, but if I recall they only have a phase reversal facility for tackling feedback. I like the versatility of the Marshall's sweepable notch filter for cutting specific frequencies as and when they give problems. Straight phase switching doesn't always do the job.