#1
Does using amp sim programs like Amplitube 3 reduce the quality of your playing. For example, when performing vibrato on the guitar , does amplitube pick that up well? Or would the vibrato sound much more better on a real amp.
#2
Check out the videos in my link, or any of my cover videos on my moopadoopolus channel on youtube.

Everything was done on Amplitube 3. I get a wide range of tones and I always get comments asking what amp I'm using.

I would say it's good, better than most solid state amps. But not quite as natural and touch responsive as a good tube amp.

I wouldn't say it reduces the quality of your playing, in fact if it makes you work harder to get vibrato, that will probably help your overall playing.

Best of luck!