I used YS and I never had any problems with them. They run so well once you understand how to tune the engine, of which is not hard at all. Not to forget using 25% nitro fuel makes her run happily. However, you can see the 160/170 are bone shakers and the wear and tear on the plane is so obvious. Heck, some even use mini servos with EP 2M patternships because of the lack of vibration from the 160/170. Then some are so fanatical, they change a new plug every few flights when competing. Tuning the engine in the morning and competing later in the afternoon will mean another potential retuning.

For me EP is the way to go for me now BUT for Q500 planes nothing beats the scream of an engine revving at 21K RPM. EP is so smooth and convenient (I am now too lazy to clean up after flying) but I did speak with quite a few F3A flyers who now moved to EP. They enjoy the smooth throttle response. They find it to be more predictable.

Downside is the batts, that is the 'weak link' now. Charging time, investment cost (best to have 4 sets in hand, 6 would be great), cost of 2 good chargers and longevity/durability of the batts. In Malaysia its weird, we have found Rhinos to be a FAILURE. Almost all bloat after 10 cycles even though we are pushing the batts to only 70% of their discharge capability. Even Turnigy ones are the same. Something must be wrong from where we come from! You guys in the US are lucky ...

At the end of the day its a personal choice.