Pucho, I would have to agree with you. I rebuilt my diff with the associated parts months ago and have not had any slippage since.
Punisher, the oneway is your best bet unless you like to throw a car around. I was at a track one time and the car was spinning out in this one corner. I thought it was because of the oneway so I pulled it out and put the diff in. That was a waste of time. The car pushed everywhere except for that one corner and it still spun out but even quicker. Upon further examination I found my rear sway bars extremely uneven which caused the spinout. Once this problem was fixed the car has not done that since. I race the car on slick tracks to high bite and always run the oneway. If your driving style is a smooth, flowing one the oneway will reward you with great corner speed which equates in low lap times. The diff is a great option for those that like to throw a car around and drive point and shoot style. Great thing is the car can be setup that way as well.
As far as parts go, since HPI got the arms and hubs into the states there is no lack of parts. I have been able to get everything except those parts since the car came out.
On the question of durability, I had a run in with a nitro sedan towards the end of the back stretch (I was passing it
, 10t motors are not supposed to be that fast I thought but my new Peak Vantage is an animal) and he moved over which launched us both completely out of the track. Needless to say I was worried but some spectators put the car back on the track and I drove it to me. The only thing that happened was his axle left a scrape on one of my wheels. A friend of mine that has a Pro4 hit a corner dot later in the day when he was in front of me. I am sure he got close to 4ft of air with 20ft of distance down the track and kept going once marshals got the car back on all 4 wheels. The car is one tough cookie.
BTW, the car was fantastic this weekend. It was my first outing with it on asphalt. Got a TQ and a win against some VERY fast drivers.