Good ink work going on there Jim. I'm curious about Manga Studio. What do you feel makes it better for inking than Photoshop?
To be honest, apart from the ~£400 difference in the price tag, I just find the pen and brush controls more intuitive. For some reason, I don't seem to be able to get Photoshop brushes to behave the way I want them to. I appreciate that this is probably more about me than it is about Photoshop, but £30 to be able to sit down and just work seemed like value for money to me ...!
Plus, in PS CS3, you can't free rotate the canvas as you work (and you still can't in Illustrator, even in CS4).
Oddly enough, I still sketch in PS, too. This is partly because I like PS' selection and compositing tools better, so it's easier to montage in reference material, select and re-size parts of the composition, and so on.
That said, I'm using PS less for this sort of thing now, and am making an effort to work solely in MSD. I'm still lettering in Illustrator, though, and whenever I get round to colour, I intend to do that in Photoshop.
Oh ... and PS CS3 crashes on me. A lot. No, really, a LOT. Manga Studio -- thus far, fingers crossed -- not at all.
Cheers!
Jim