I must say, we're kind of newbie here.
We found i-mscp just fits our needs (coming from the heavy 'plesk'), and it's almost perfect (just missing some backup features, but from what I've heard they're coming soon). We tried many different panels before choosing imscp, and the only thing we really believe it's really poor is the design. Despite the new logo is great, it's not showed anywhere in the panel, and looks like the ui just stocked in the past.
Would be great to have a nicer desing, minimalistic and bootstraped.
We tried to made a few changes, but it's difficult as every update they're down again, so maybe imscp needs a 'real' template system, including login/404/500 page errors. Anyway, we can keep working on it if some people are interested on our work, and also able to colaborate.
Attached is a screenshot of the login screen (is not a mockup, it's really our modificacions in production). PS: sorry for the language, is spanish as is our panel
Any suggestions or comments will be welcome!