I have a RP6. Made several mods using Groovetracer. Dropped counterweight and subplatter. Subplatter made an immediate and amazing difference. Hugely improved bass and general musicality. If the subplatter on the Planar 3 is still some type of plastic, I would get the Groovetracer mod as soon as possible.
The new Rega Planar 3
Rega has just launched the Planar 3 2016... only two components remain from the previous RP3. The high-gloss finish looks cool... black and white only. http://goo.gl/6JdX2Q