Without getting into technicalities...
Best sound with most modern and post 50's records is achieved in the following order... (worst to best)
Conical / Spherical (cheapest option)
Line Contact / Shibata / HyperEliptical / FineLine / VitalLine - Pricing starts at $50, most are around $100
Exotic Proprietary shapes (MicrLine, SAS, Pathfinder, FritzGeiger, Replicant etc...) - Pricing starts at #140 and the sky is the limit
The other aspect is that line contact styli have lower wear (both the stylus and the records) so everything lasts longer and better.
Typically a Line Contact stylus can be expected to have 3 times the life of an eliptical or conical (all things being equal...) - so although more expensive, they do frequently provide great value.
My own approach is that the minimum choice I would opt for would be a 0.4 mil eliptical (although you should be able to find a 0.3mil at almost the same price!) - but if at all possible, a Line contact stylus is a far better option.
(Note the M55 cartridge was the same as the M44 - with an eliptical stylus fitted, so the elipticals are often labelled N55E...)
Here are some good elipticalshttp://www.turntableneedles.com/N55E-Ty ... _4039.htmlhttp://www.edsaunders.com/shurestylus.htmhttp://stylus.export-japan.com/product_ ... ts_id=1014http://www.lpgear.com/product/SHSM0055EM.html
Here is the "ultimate" needle for the M44http://www.lpgear.com/product/eSHN055E.html
I have not been able to track down any standard line contact types for the M44/M55/V15-I (same mounting)
So the list goes straight from eliptical up to SAS - which is a HUGE jump
bye for now