I cannot afford the higher end harps. I am sure they are as different as night and day! I have a Marine Band, I like it's sound but the reed plates cut my lips until the wood swells, then it is like playing a chainsaw. I haven't bothered with trimming and sealing it.
I have a set of 7 Special 20s. I like them VERY much and highly recommend them for good affordable harps to learn on, my first two (C&G) are roughly 6 years old and play as well as the day I bought them.(It's me that has improved

).
I have bought a Suzuki BluesMaster. It is a very nice harp, easy to bend, sounds good. This is also a great affordable harp to learn on.
Of these 3 harps I prefer the Special 20. I am thinking about buying a MANJI next. I hope to be able to afford a SEDYLE in the future. I've read many great things about these harps. The CROSSOVER is also on my "wanna get list".