Just wunderin if anyone has used bi-tron and has an opinion on it.

I took a look at the video and read some of the literature and it sounds very promising.
Should be worth a try..

I might have to grab a bit of their additive for my diff.

I have used the product for a quite few years figuring that if it works a fraction of what they claim it is worth it. I loaned my car to my son one night to do a favour for me about 40min drive there and another 40 back most of it on the M1 in Brisbane, when he arrived home I could hear the car rattling away like a freight train(said he could not hear it cause he and his mate had the stereo turned up) checked it out and the oil pressure sender on the motor had blown the end out and pumped out the oil, thought out quite loud that that would be the end of that motor however replaced the sender and filled it with oil again started it up rattled for a bit till it got the oil through it again and ran as if nothing happened, this motor had over 200,000klms on it yet I drove it around for nearly another 2years before I replaced it with a new motor (gtp40 heads, cam, r rockers) and it was still going strong, I put it down to the bitron, I may be wrong but like I said if it does a fraction as what they say it does it is well worth it. I forgot to mention the place he drove to that night about 40 mins away rang me after he got home to tell me that my car had left a heap of oil on his driveway.