Soft and sharp is best for underbasing or heavier ink deposits. I don't mind triple duros and we use the beveled blades a good bit but most of our printing is done with Smiling Jacks, Manny's, and Dr J's with a special blade for white that isn't for sale yet. If you're push stroking on a manual, the beveled blades don't work well, and the traditional blade shape works best and the triple is probably your best bet. Automatic printing is where we find the special blades really matter, and not really until you start doing some really difficult things like one hit whites, one hit "whatever color" on mediums and darks, process work etc. Just your every day stuff and using the mesh and stencil to meter ink deposit the specialty blades aren't going to give you a noticeable change in quality or ink deposit but when you are pushing the mesh to it's maximum potential is when I see the difference in blade profile and performance.
Too soft of a blade and the push stroke doesn't work well and the SJ, Dr J and Manny give you a small leg up when push stroking although I do think Joe's blades are better than all other blades simply because they last much longer and are two blades in one. I find they perform better overall but it's not that noticeable on a lot of standard stuff but the durability and two completely different ink deposits with one blade sell me in their use. I get one hit whites all the time on the manual press with just a standard 70 duro blade but I know that triple duro's are better for most shops that are having to get thick plastisol through small mesh openings and are using medium and high pressures to print with.