I have a GK 1001RB-II which is small and light enough for me, I just miss the lack of tube sound sometimes. You can get it pretty warm, but I would still prefer the tube inside for at least some tube gain.
That's why I'm leaning towards the GK Fusion series, the 550 model for ex. or something hybrid from Aguilar.
I also heard that the Tonehammer from Aguilar produces a killer sound, and is light and small aswell. I personally like that head, guess I'm a kind of an Aguilar boy... hehe.
It's just that when you hear an Aguilar head+box set or Aguilar head+bergantino box you just don't want to hear nothing else anymore