oh yeah are flats smoother they eliminate any extra fret/finger moise and fatten up your bottom and middle. i personally use the fender ones i put a set on my fretless 6 yrs ago and they have been on 2 other basses (tha same pack of strings) now my jaguar with very little tone loss.
get them if you want that vintage 60's thump. any good guitar /bass shop will order them or try online for better prices