I have and use both, it mostly depends on the size of stock I'm budding, 90% of the time I use my knife that has a separate lifter, but that's because I use it to graft other stock besides citrus (peaches, apples, ect.ect) allot of the time when I'm budding seedling citrus the separate blade is a hassle to turn around to pull the bark off so I just use my fingernail instead.. "If your bark is slipping well like it should you don't really need a bark lifter" Young seedlings don't have any real bark in the first place. Production budder's seem to use the lifter on the blade type. You'll find no matter what one you get, you'll get use to using it.. "you will adapt to the blade"
If your not doing small stock all day and will end up grafting other material the better knife for all purpose would be a separate bark lifter..