Sizes of various X61/X61s batteries?

I'm looking to purchase a new notebook from Lenovo, but before I do, I have a burning question that I can't seem to get answered by either a quick google search or at Lenovo's site.

I realize that the "8 cell" batteries for both the X61 and X61s hang out the back. While weight is important to me, size is more so. Does the 4 cell battery "hang out" past the back of the laptop?

In addition, I noticed the X61s has two different 4 cell batteries, the "Enhanced Capacity" model and the "Slim Line" model. I think I can safely assume that the Slim Line model is the "prismatic" battery mentioned in the spec PDF, and that it lies flush with the back of the laptop. However, does the 4 cell Enhanced Capacity battery also lie flush (or close to it)? Is the X61s' enhanced capacity battery the exact same as the X61 4 cell battery? How much, if any, does that hang out the back of the laptop (spec sheets give only one dimension regardless of the battery size, and I *know* the 8 cells hang way out).

Thanks in advance!
Orum

 

I believe the enhanced battery does sit flush with the case. It does however stick out a bit from the bottom which raises the rear a smidge.