Feature:
Came with a foot switch. made of metal.

Quality:
There are a lot of wonderful amps out there. fenders, Mesa, carvin, but marshall will meet or exceed anybody for quality.

Value:
I always wish they could do it cheaper, and the merchant be happy with a smaller mark-up, but I have not regretted what I paid for these amps.

Desirability:
great looking amp. Sexy? I guess not, but I'm not really attracted to amplifiers. I just want them to produce an inspiring sound. This amp can do that.

Sound:
I bought two of these in 2000 to use with a chorus/delay/flanger setup.. I haven't had any problems. (From the downloaded picture, I'm not sure if these 50's are the same as the models I own. It looks here like the control configuration has changed a bit.) I use them everyday. They are plenty loud for smaller (club size) venues. They work very well with Boss, Morley, Electro-harmonix. Respond very well, and they have that Marshall character, and sound. If these newer versions are anything liike what I've been using, then I would sincerely recommend them. They are a little on the spendy side, but you will notice the Marshall quality.

Ease of Use:
Marshall will include a very helpful (and clearly written) instruction booklet to give you some suggested settings. Then you can modify from there. This amp does have one quirk. You must let it warm up for at least 5 minutes before you start wailing away. It does need that tube warm up time.

Support:
Haven't had any real problems. Did need a couple of tubes after a long period of daily use of at least 2 to 4 hours nearly everyday since 2000. These amps have performed flawlessly for me. I have heard about the cooling fans going out, but I have not, nor do I know anyone who has had that problem.

Overall:
I expect this amp to keep serving me for a long, long time. It has a specific task. It does it well. I would replace it if it were damged in transport.