The HD 147 is a great amp. Extremely good as a practice amp and a band rehearsal amp, as it is very light weight yet very powerful. I would love to get one for to replace that for my Spider II, and would feel confident enough to gig with it. Nothing really beats tubes but out in the crowd they wouldn't be able to tell the difference.
If you need versatility and multiple tones and effects, want a light weight amp that gets the job done, I would say get it, however if you are looking for one really good tone, I would do as Guru said and get a tube amp. Depends on what you want.