Not sure what kind of prop/rpm's you are getting on the 120, but my dle turns a vess 17x6 about 8300 rpm's at 3100' of alt. I had a ys 110s that turned the same prop at 8900-9000 rpm's. Both engines where on a OMP Fusion. The YS 110 had lots more power, but I have the DLE 20 on the fusion as it flies it great, but sips the fuel. Most people running the vess 17x6 get around 8200-8600 pending where they are at, etc...

Hope this helps. I love my dle 20, miss the power of the YS 110s, but don't miss the fuel bill, nor the mess.