Re: Marshall 1w or ht metal 1c ?
You're sort of comparing apples to oranges here, b/c the Blackstar is made to a much lower price point than the Marshall 1 watters or SL5. And the Marshalls are different from each other.
It's not a surprise that you couldn't get good cleans out of the HT1MC. That's not what it's made for.
SL5 seems to be a great amp (especially the fact that it goes down to 1 watt), but it can be hard to find, and it's as expensive as the 1 watters.
JCM1 indeed seems to have good tones. You don't get a dedicated clean channel like the DSL1, but the dirt channel has a gain boost.
If you want to play blues and EVH, I'd point you to the DSL1, JCM1, or JMP1 (just roll down guitar volume for cleans). Maybe Randall RD1 (I've only played the RD5, which is very decent).
If you want metal, go for the HT1MC or JVM1.
You need to figure out which features you need/want - dedicated clean channel, effects loop, certain amount of gain, etc. Also, balance against whatever your budget allows
