Typical, late again as I've only just seen this post Two things, firstly regarding the MB-D10 grip.
<<I used the battery only in the grip and didn't put one in the camera>>
Trouble with that is that doesn't only one battery get charge cycled. I use two batteries and when the D10 runs down, charge it and put it in camera. By reversing them it may improve the life.
Regarding camera straps, I bought the Sun Sniper sniperpro see http://www.sun-sniper.com/en/sniper-strap-the-pro-steel-bear.html I find this strap superb as it takes all the weight off the neck. Also, as I often carry a long telephoto lens it screws into the tripod foot and balances superbly. I guess it's a similar product to the Black rapid.