Has anybody tried the kits that are available to drop the back down an inch.  Have put longer shocks on and want to drop it back to the original height.

Had the lowering blocks on when I had the stock 13" shocks on mate. I still have them and your quote welcome to have them but I assume the blocks for my year bike would be different to your new bike.

As for ride quality I didn't notice that much of a difference they just did their job lowering the bike by an inch.