Gotta agree: for lower volumes SS shine, but for higher volumes it's tubes. I also have a modeling amp (a Vypyr 75 watt) with good sounds...decent at lower volumes, but better at more volume.
Regarding the Fender Blues jr., I've had one for a number of years and don't be fooled by the 15 watts, It's loud and sounds best @loud volume. Not so great @ low volumes IMO.
Also I like my Ibanez TSA15H; it's a very good sounding smaller tube amp...respectable at lower vol. but best turned up using the full 15 watt mode. It has a feature that allows switching to 5 watts and sounds great at lower volumes. They also make it in a combo version now.
Also have a Blackstar HT20H (20 watt tube head) and again, sounds it's best @ higher volumes and it can get very loud! There are great reviews on the smaller Blackstars (both the 1 watt and the 5 watt). I love the HT20H, but not at bedroom volumes.
So if it's tone at low volumes you're looking for, I'd recommend test driving the Ibanez TSA15, or the HT1 or HT5 Blackstar. And that's my 2 cents worth