I've got both a TREXCELL & INCREDICELL(don't recommend the INCREDICELL).
The battery covers are equal, if not exactly the same.
Care does need to be taken when removing the cover, especially around the kickstand area, as that is the weakest point on the cover due to the contours that are present to accommodate the extended battery thickness.
Not a big deal, or, deal breaker. You can get replacement covers by simply buying an el cheapo extended battery for a few $ on e-Bay, AMAZON, etc.......
SEIDIO will sell the extended battery cover by itself, for $14..95.
You simply just have to call & ask for it, unless SEIDIO has begun listing them on their website.