We originally flew LEU Treehugger with a half VW (29 HP, per wood bar dyno test), then put on the 3VW Verner. Result was much improved TO, climb, speed. It is fun to fly now - no anxieties on clearing the trees. We had it at Oshkosh in 2018, as well as Les Homan with his newer updated 3V model on his LEXL.
Our DE Stubby flies with a 2180cc Great Plains VW engine, and flies well with one heavier pilot or two light persons. Based on our experience with the LEU, I would think the Verner 5S engine would be amazing on a DE. It is lighter than the VW, and produces more HP at lower rpms, allowing a longer prop. It would be a great climber. But, that engine is "pricey".
The lower cost 5V produces 60 HP, which is about 5 - 10 HP less than our 2180 VW, but at lower rpms. Only my guestimate, but it may produce a bit better climb due to a longer prop, and could increase cruise a bit.
I hope someone tries one of these engines on a DE - should be fun.
