My 01 T5 is getting up in age and miles 220K to be exact. I have been looking at V70 / S60R's. Have done my research also and I am still undecided.
Yes the R has more power but does the weight increase of the AWD system counter act the gain. Yes both models have pros and cons so the question is is the R worth it?

 

Just curious, I just bought a 2001 V70 T5 with no issues at 200K. You having problems with yours? I looked at an R, but decided against it because I'm using it as a DD. With 18's and being heavier I opted for less expensive tires and better gas mileage.

 

I use mine as a daily driver also. I had the Volvo transmission issues and the tranny rebuilt last year at cost of $3500. Other wise it was just the usual wear and tear items. I am going to keep my t5 for as long as she runs. I know this car inside and out a I do most of the work myself. An that's the part the is the scarest in buying a used Volvo is the history and with the R's is the risk of buyin one and have the awe system go and the cost of replacing it is about $4000