post up how you like em. ive been considering these but it looks like if you are using the rear stand with them, there will be nothing holding them in place when you pull the axle out. the axle holds them tight to the swingarm but when you pull the axle it looks like they would just flop out and if you are using the brackets for the stand with them the biike would fall over... maybe i missed something
If you have them drilled in (1of the 2 ways to install) they will be securely fitted and allow for quick wheel changes. The 2nd option has the problem you noted, but they still help with proper wheel alignment and are easier to align by ones-self when fitting tire-warmers.(Plus they totally look the business- hahaha)
I have mine drilled in to allow for quick wheel changes, but I change tires once every 7,000miles and usually utilize the weak-welded spool bosses with some bolts or my universal T-Rex rear stand.
As for them cracking............I've had no problem with them and have run them for 38,000+miles w/2 wrecks. I am actually selling my two GP lifters and buying new shiny ones so I won't have my rashed up ones.
Lightech also make some but they don't appear to have the option to be drilled in like the Gilles.
EDIT: The bolt in the front that usually holds the adjuster block - holds the chain adjuster in place with enough force to change the wheel. However, I wouldn't suggest having the axle out and po-going on the bike while it's on the stand via GP lifters!!! ( or any stands for that matter)