This will not really help you if you have a BMW diff, but thought I wouild post anyway! My Titan lasted less than 4 years (and I am told that this was good going!) before it had to come out and have a rebuild (few track days and several road trips) - new Belleville springs required. Had a long chat to Steve Perks about the various designs etc (also looked at the various components at his workshop to compare his and Titan's) and persuaded his unit is better for three main reasons - larger friction plates able to cope better with the huge loads transmitted through the diff, Belleville springs are better quality and are not compressed fully in the Tracsport unit (as they evidently are in the Titan) which means they do not lose function and thirdly the ramp block walls are thicker meaning more surface area contact on the cross pins meaning less risk of steel fatigue and damage to the ramp blocks and pins! Have now fitted the Tracsport but not been able to drive much for reasons we all understand. Road and Race say the Titan diff will generally need to come out every few years for a rebuild (which is not too expensive if you are able to take the diff out yourself!) Steve Perks says his Tracsport unit should not need these regular rebuilds. Will have to report back in several years on that! As mentioned in a post above Palmer sports are now into their second season running Tracsports and no problems so far. I understand when they were running Titan diffs they were having to have them rebuilt once or twice a season! I understand that Tracsport offer a smaller range of ramp angles, but cannot really comment on that as I have not got to grips with understanding the implications of this!