Personally, I'll never be going back to solid states. I had a Fender Mustang I for almost the first year of playing, but recently I bought the Blackstar HT-1R (a 1 Watt tube amp), and it sounds so much better, especially for clean tones and rock/metal lead with distortion.

I will say the Mustang was pretty good for that crunchy rock tone and distorted power chords, but the lead tone is pretty crappy.

I would recommend the Blackstart HT-1R. A little more expensive, but sounds great.