Here in Germany Oliver is quite popular and I strung many of them.
The list of models I have strung:
- Dual Tec
- Spectros 305
- MicroTec 08
- Phantom X9
- Flexter PC
- Fetter Smash (lol the name)
Stiffness-wise they are not wet noodles, but even in Yonex and Victors “Stiff” rating there is a variance. IMO they are close and just a bit more flexible.
All in all I wouldn’t recommend Oliver. The cheaper models are quite good for entry/beginner level. The higher priced models are not worth the price. Despite the awkward stringing pattern on a few of them, which don’t work well with my clamps, the quality of the material is not the best. Have seen a few (Microtec08 and Dual Tec) sinking at quite low tensions (10kg).
It seems you look for Extra Stiff rackets. Do you new FZ Forza? Their rackets are much better quality and x-stiff is really x-stiff.