1) I have no intention of exceeding 4" of suspension lift. Additional clearance I might need will be attained via a tummy tuck (soon) & fender modifications. At 4", no LA kit that I know of will reasonably exceed the performance of the SA kit from Savvy, on-road or off. And even if there is one, I'll never have the bank or time to build my rig beyond the capability of that Savvy kit.
2) A SA kit is much easier to install (no welding, cutting, painting, etc.). I can easily do it myself over the weekend.
3) A quality LA kit with all the components like this one from Clayton:
http://claytonoffroad.com/product_info.php/cPath/17_40/products_id/135
... is much more expensive, even before the significant "hidden" cost of a much more complex install.
4) I'm about to bite into a JKU project soon because the monkeys AND my newfie pup just don't fit in the TJ anymore.