Sounds great that you had fun at your club and being able to race with a TCS driver. I had the privilege of driving against an HPI and Yokomo team drivers back in the day. Needless to say, they smoked all our local's butts.

As for bearings, I am using the Tamiya bearings that came with the V2 kit. I don't know how much better it is or not vs my Duratrax bearings but they feel much smoother.

As for bearing maintenance, most often than not, I just replace with new. I usually can't get all the grit out and even if I did, the balls feel worn inside so just replace them all together when they feel too loose, too dry (hard to explain), or grinding feel.

I've seen and read about bearing maintenance, soaking them in motor spray what not. May sound ironic as I reuse wheels in good condition, but bearings is something I don't usually reuse if they don't feel right. I just toss them.

For low drag, a high grade metal shielded bearing is in most, let me repeat, in most cases the best. i believe that it wasn't in the bearings tho. Probably more in the detail and a set up item than just the bearings.