Multitools - ah yes, another obsession.
Swiss Tool (RS is my favorite but X is good too) - by far and away the best. I have done complete marine installation projects with this tool. The tool selection is terrific, it is extremely tough and durable, sturdy. Knife blades, Fit and finish is extraordinary - no other multitool comes close. The *only* deficit is that the knife blades should be one handed opening.
Leatherman Wave - an 'ok' tool for light use. The one handed knife opening is great and the size is nicer (smaller than Swiss Tool). I carry the Leatherman when I anticipate having to use the knife a lot or when smaller is ok. If you have to really torque a screw, the blades twist, the handles twist and it sort of feels like the tool will come apart. Very different than the experience with the Swiss Tool.
Leatherman Juice XE6 - my EDC carry tool. Works ok for the day to day tasks, especially at the office or fixing light equipment. More discrete since you can carry this in a pocket.
Swiss Cyber Tool 34 - the end all and be all tool if you have to ever work on electronics like computers. This is the only tool you will need and it is exceptional.
I carry the Swiss tool probably 80% of the time when not at work (office environment), the Wave the 20%. XE6 whenever I can't wear my belt holster (church, office etc...). Cyber tool is in my briefcase 24/7.
For belt holsters/sheaths there is nothing better than what you can get from Dix Leatherworks. I have ordered a lot of sheaths for multitools, flashlights, etc.. from them. Check it out, inexpensive, very high quality - highly recommended:
http://www.leatherwork.com
J