The most noticeable difference is size or the working length. Most personal SRLs are offered in lengths of 6-12 feet. Anything longer can become difficult to manage. Since these devices are generally used interchangeably with energy absorbing lanyards, there is an expectation that they be small and reasonably lightweight.
Another difference is material. The constituent line in a personal SRL is typically webbing to lower the size and weight. Larger, full-size SRLs more frequently use wire rope. Wire rope is heavier and requires a wider drum diameter to be effectively wound.
Finally, most full size SRLs utilize an internal rotary brake to manage energy absorption. With size and weight constraints for personal devices, this is considered impractical. External tear-tape energy absorbers are generally used on smaller devices.