If you think about it ,turn an engine at 16,000 rpm instead of 12,000 your wear out your engine by 25% more so lets say at 12,000 your engine lasts 4 years and at 16,000 3 years. buy the bigger engine and turn at less RPM for power. Pocket the savings in lower cost of fuel toward the next purchase of replacement engine and at an extra year later.
That may be but these model engines are relatively cheap. And I have rarely worn out even the higher reving ones. I could save money by not being in this hobby and generally more power is more fun. Still I have a couple of low nitro engines. One of them has a good low idle, but it does shake a bit, but it is a lowly ASP. But generally increased compression or cylinder pinch will make it shake more, but if a well built smooth runner on a strong plastic mount I doubt it would be that noticable.