I have just got my technics bearing back from Vantage Audio (http://www.vantageaudio.com/) after a level 1 upgrade which essentially consists of a new thrust pad with integral oil well and thrust pad support.
I shipped them my old bearing (well brand new actually so as to get the most out of the upgrade) and got it back after 4 days including a 24 hour test bench run - pretty darned impressive service and all for a miserly £82.
So any difference to the standard bearing? I should preface my response by saying that after getting my Decca Blue setup correctly last week my system has never ever sounded so good.
The difference is subtle but most definitely audible and becomes more obvious the more one listens - especially complex pieces.
The first thing I noticed was that vocals were more "expressive" (probably the wrong word) but on long-held notes - especially going up and down scale I can hear much more of the natural variance in vocalisation and inflection - it imparts a more natural "live" sound - it's like hearing subtle differences in regional accents. Having heard this difference I then became aware of similar differences in instrument "voices" - especially sustained notes such as bass guitar, harpsichord, piano where there is more detail to the trailing edges of notes than before. Interestingly, while the biggest changes to my ears are in these "harmonics" and "inflections" there is also no doubt that fast notes start and stop with more control - so plucked strings have better definition. Bass guitar "riffs" already well presented before are now that bit more defined and controlled. There has been no change to the essentials of PRaT or sound presentation/stereo imagery.
So not a night & day improvement but an improvement nonetheless. I suspect that when replay kit gets to this level then improvements of necessity will be small and incremental.
I am very pleased with what I got for my £82 and very impressed with the service and communication I received at all stages from Vantage Audio.
Steve