I had the RX1 first. RX1R second. Had a few issues with my RX1 after several months of ownership. Sony replaces it, and I exchanged for the RX1R.
Personally, I think I would be okay staying with the RX1 after trying both. Yes, the RX1R is marginally sharper, but I feel like is is also more contrasty as well, which I could do without. I find I end up recovering a little more on the darks to get me where I was with the RX1.
All in all, if you want the best dynamic range, the RX1 might be marginally better. If you want the best sharpness, the RX1R is the ticket, but just marginally I think.
I wouldn't waste coin making the switch. But, that's just me. Both are simply incredible.