jlank,

For props, it really depends on what you're looking to do.

I'm running a H9 Twist as well, but with a Magnum 91 4-stroke. I originally ran Zinger props because they were readily available and relatively inexpensive...

But I found that on the Twist, where I wanted that thrust for 3D/funfly stuff, the Zingers didn't work all that well. Not bad, but I felt it could be better. After some experimenting, I ended up with an APC 15x4W and really liked it. Lots of "umph"...

With a 70, I'd try the APC 13x4W. A friend runs this on a Magnum 70 (similar performance to your OS 70) and it works well, spinning around 10k RPM static. You will notice the spool-up is a bit slower, since it's a wide-blade heavy prop, but these props seem to really beat the air and generate a lot of thrust.

As far as your throttle is concerned, I don't seem to notice this on my engines.... I can hover at less than 1/2 throttle, then go up to 3/4 for a graceful pull-out or jam it all the way to full for rocketing out of it. Have you checked your linkage as RaceCity mentions? Are you able to go to full throttle without the throttle servo buzzing and/or bending the wire? Are you using end-point adjustments (EPA) to keep this from happening? If so, you should readjust your linkage so you have full throw from 0 to full with no EPA adjustment.

Hope this helps...