The two comments from the AAC Pilots are fair. From a Soldier Pilots point of view I wouldn't advice you to come through that route, we do get the lion share of the flying but most of the fun has gone. The 'AH' thing is all the rage, if your not 'AH', your not!
I honestly don't think any flying experience will be of any use to you what so ever, on Grading or any other part of the course. The Theory side of it will, but don't confuse Mil' Flying with Civil, very different!
If your passion is to fly, I think you should take another look at the RAF. You are obviously interested in Helicopters if you are looking at the AAC, I think you will find that the RAF Heli' guys get quite alot of time in the saddle.
Hope that helps. Best of luck anyway.
(AAC WO2 on Lynx)