Using Photoshop CC for awhile and seeing this program pop up o my recommended list every time I go on Amazon so it makes me wonder; How good is it?
Its alright. If you already have Photoshop the only area I could see it having an advantage is in digital inking.
if you want a nicer inking experience though I would personally would just grab this guys inking brush. My experience with his brushes back when I was using Photoshop was very positive.
https://gumroad.com/kyletwebster
Doesn't seem like I can pay with paypal sadly unless Im blind and I'm missing it. But his brushes look very good, I just don't have a credit card to purchase with :/
That sucks. It would still be worth while though to grab his wet and wild watercolor brush and mr natural inking brush since they are pay what you like. Just set the price at zero and you wont have to enter a credit card.
As for manga studio just give the trial a go and see how you like it. But if you do end up liking and buying it if its not too much more at the time I would to get the digital version Clip Studio Pro since apparently it is updated more often.
http://www.clipstudio.net/en