Both my L2P and L1P that I have came fairly well lubricated and had no problems with the o-rings. I've had both of them for less than 6 weeks, so I don't know if I just got lucky or it was more of a problem on earlier lights.
Kas, as far as lubricants go there are several answers and it seems most CPF members have their own preference. If you do some searches you will find a wealth of information. I have some of the Radio Shack Multi-Purpose Lube Gel, which is silicone based. I bought it because Peter Gransee recommended it, it was locally available, and it cost $1 for a fairly large tube (about the same size as an average toothpaste tube).
I would like to try some of the NyoGel product, but will wait until I buy something from one of the sites that carry it. If I just use the Radio Shack stuff I have on flashlights it should last for many, many years.