We have talked and I know how much you are struggling with this decision. I am struggling with the same decision and I was almost decided upon a 6.5X47, when I went back to the 6.5X55 and the 260.
The "winningest" 6.5 mm long range cartridge is still the 6.5X284, but it comes at a huge cost in terms of barrel life.
The best barrel life of your choices is the 6.5X47, but I have to agree with Richard and from my own personal interaction with some very good shooters, including D. Lapierre, (Arguably the best benchrest and F-Class shooter in BC) there have been many that have had difficulty making this cartridge work for them, yet I can also say that an equal number have made them sing. I have not seen a 6.5X47 win any BCRA competition in BC though. You will here from many guys that have had great success with it (And most of the 6.5 barrels I sell are destined for the 6.5 Lapua cartridge and I get lots of great feedback) , but I haven't seen that in competition locally - that is just a highly personal and subjective conclusion .
The 260 is a very easy cartridge to make work, as is the 6.5X55. Conversely, I also know shooters that have had tremendous difficulty making the Swede AI work well, but the 260AI seems to be less temperamental.
I have put the 260, the 260 AI and the Swede on my short list for my next 6.5
Since I will likely be team shooting with CyaN1de this year, it makes sense to standardize the cartridge we use for coaching purposes, and lucky for me, he has firmly made up his mind, thus I will likely bum his reamer and build a 260 "Habu" as well.