I've got a pair of 5W Goldstars (actually a 1x10 combo and slave 1x10 power amp combo) and a friend has a 10W. The 5W is an brilliant amp for home use. Tiny, can crank it without it taking your head off. The neighbours can still just about hear it full up, but it's by no means loud in amp terms. Sounds really bloody good and works well with pedals. Same goes for the 10W except it's quite a lot louder and tighter.
Ours are the old single channel versions. Mine has a loop in it which is excellent. I don't have the boost switch and power scaling is fairly redundant on a small amp.
HOWEVER...
If you are planning on a Goldstar, Martin still has an offer on using my old Goldstar head case (mint, never left the house) and a set of Roadstar transformers he has spare. I believe he's offering a Roadstar 18W for £545 with power scaling. The Roadstar with scaling is one of the nicest sounding amps I've heard and it'll certainly do lower vols. Indeed if I didn't already have enough amps, I'd have been on that like a shot. He's posted about it before on The Fretboard, but give him a call if he's got the bits I'd jump on that over the Goldstar.
