Rega, Pro-Ject, Technics SL-1200

A few months ago I bought a SL-1200 M3D and put a Shure M97xe cartridge on it soon after. Its not nearly broke in but I have to say while it sounds ok its not what I consider "audiophile" quality or at least not yet. And in no way is this a slam against the 1200. A buddy of mine let me borrow his Pro-Ject RM5.1SE that comes with the MC Sumiko Blue Point and 9" carbon fiber tone arm. Honestly after comparing the 2 last night the Pro-Ject was the clear winner. Not that the Technics sounds bad at all but I would say rather on the thin or edgy in comparison. My question is how does Rega lets say a P3 or P5 compare to the RM5.1SE? What is each mfg house sound? I know the Technics can be upgraded by KAB but not sure its worth the cost or time. I am just getting into vinyl so not really too experienced when it comes to different manufacturers and value per dollar. Seems the Rega has more upgrade path from what I've seen. The RM5.1SE does sound very sweet but not sure how it would compare against a P3 or P5?