I did a bit of comparison work a couple of years back on the PSU with my P5. I found changing to the 'white belt' had a similar affect on the sound, I also had a low level hum issue when the PSU was used, the dealer was helpful, he phoned Rega, re did the earth conection in the PSU, but the hum was not totaly eliminated, The set up in those days was fairly standard, Rega arm, Ortofon M2 Blue, not sure I had changed the sub-platter at that time?
I think the new PSUs may be better on hum? . . . but over all, £20 for a white belt was a better beal. I stear clear of 45rpm recordings, as the faffing about to change speed aint worth it for me, however, if you have lots of 45rpm records, and you think £200 is OK . . . ???
I recon you would do better investing the money in a new after market Sub-platter, a White Belt and a Ceramic bearing? All will have their positive affect on your sound.
Only my humble opinion of course.
CJSF