I'm also currently diving an AquaLung Titan LX that I got a whole set, (AquaLung Titan LX, Aqualung octo, Suunto SPG) for $350 with 9 dives on it. Nice durable regulator that performs good in cold water, but once you take it to depth the performance changes, and since my thread I made on it I've dove 2 more in the same conditions (to any of you who may have been involved in that discussion) of the same year and model make, and I got the same result: less performance (very very very light performance drop at around 40ft, the further you go the greater the performance drop). Topped out at 74 REAL FEET- not the "add 10 for cold water" rule and that's about where it got to the point (on all 3 regs, all different setups, tuned and serviced and owned by different people) where it was too iffy to comfortably go lower with the dive
EDIT: Just to clarify, these were all AquaLung Titan LX regs from the exact same model year (I think somewhere around 2006, it was when the first stage was labeled "Aqualung Titan", and the primary second stage only had "LX" on it)