Well, to throw in my $.02 worth, I run an Enya .15 baffle piston and have run an OS .35 iron piston engine, and depending on the type of aircraft and flying you want to do, I don't see where a more modern engine will be necessarily "better". Now if you are looking to 3-d and want unlimited vertical, no, they won't cut it. But for a dependable sport plane type engine I'd use what I have. Just remember to use at least 20% oil with some castor in them and they'll be happy and live a long time.
Oh, and I didn't remember the Veco .19 being that large of an engine. But it's been awhile since I've seen one. I know the Enya .15 is small even compared to the modern engines in its class.
The main thing is have fun and do what you want. I get a kick out of having something a little different from the other guys at the field.