I have used a LH SR20 in 243 for the last 20 years and have re-zeroed it four times - 3 were due to scope changes and once when RWS changed their loading of 100 gn bullets. If I do my bit it clover leafs.

A good close friend an SR21 in 308 and that too is a very nice rifle - solidly built and accurate. Some early SR21's had a slight bedding problem in that the magazine well forms part of the bedding, with either end of the action supported on wood. If this dries out over time the action can see-saw and in rapid shot strings groups can open. Solution is a very simple application of some bedding compound around the front and tang of the action. Friends rifle developed this. Had it bedded, now clover leafs again all day long.

My only real criticism of the SR21 is that its really a magazine fed rifle. But saying that dumping a round in the ejection port and pushing bolt forward is simple and it feeds easily.

I see that the precision now comes with a GRS Laminated fully adjustable stock. The Precision is also a heavier barrelled rifle. My SR20 with a 4-12x50 Swarovski weighs in a 9 1/2 lbs, and the standard SR21 is on a par with this. Its up to you to decide whether you need / want the heavier version - very much depends on your style of shooting. For me, I am a deer stalker and I have no issue taking a shot at 200 yards with mine. But I am not shooting long shot strings at very distant targets.

Edit - just found this article http://www.gunmart.net/gun-reviews/firearms/rifles/heym-sr21-precision-repeterier-grs and http://www.shootinguk.co.uk/reviews/rifle/heym-precision-sr21-rifle-review