I have owned an R5 for about a year ( from Marlin at Frontier ) and have shot about 20 rounds each weekend since. Overall, the fit and finish was good but while I personally like the stock very much and it 'fits' me some of my buddies found the palm swell too large for comfort so (as with any rifle I guess) if at all possible see how it fits you. I also put on a Blackhawk Industries cheekpiece for comfort as I am using high rings with the Falcon Menace that sits on the rifle and I found the cheekpiece eliminates a slightly annoying and high pitched vibration tone that comes through the stock after a round is fired.
Re accuracy, I have used 168 gr Hornaday HPBT but the bullet my particular rifle likes most is the SMK 175 gr HPBT. For propellant, I have used 41.7 to 44 gr of Varget and my best results are with the 175 gr SMK and 43 gr of Varget ( incidentally, 43 gr of Varget above the Sierra manual recommended max but within the Varget recommended range as listed in the Hogdon Powder manual ). With this combo I simply cannot put all bullets thru the same hole or match the results reported in reviews because I can't shoot that well, but I can comment upon the real-World accuracy I achieve and if I do my part I can get the holes to touch at 100 and can produce a 2.75" 5 shot group at 300. I strongly suspect that in the hands of a more competent shooter the rifle would be much more accurate.
Would I buy this rifle again ? Yes, no doubt.