I've got one that i'm buildling now... ceramic hybrid bearings and hyway 45mm top end. I dunno how much port work i'm going to attempt, as it would be my first port job....but I already cut 20thow off the base adapter so I can run it w/o deleting the gasket. Funny thing is that after all the 350's i played w/ this summer, the one I use the most is the one that I made up out of the junkiest parts I could find. Turns out it cuts pretty good
I think the 350's are really easy to work on... after playing w/ a bunch of them, they are a little complex and "unlikely" of a design, but w/ the right tools they come apart in a hurry, and go back together in a hurry. I see basically zero downside to the plastic case w/ the exception of melting. even so, its not THAT difficult to swap a case.... even if ebay has them for $60 or so each. That said, you can EASILY spend waYYYYYY too much $$ on parts on these. ...hence my huge CC bill this summer!
best of luck workin on yours!