I'm looking for the pros and cons of both of these engines. Will be buying one this size soon and want to get some opinions on both. I'm just looking for opinions and don't need to read anyone bashing one or the other.
Thanks

Both make great engines. Can't really go wrong with either. I tend to believe that DA offers better service than 3W. I have my reasons, but I just leave it with you as my opinion. Oops, no opinions. OK, had a buddy send in a 3W150 and a DA150 for "service". Both were about the same age and needed similar work. 3W service center charged several hundred dollars, which was fair, but DA didn't charge a penny.

I ran 3w engines with the old style crankcase for 2 years with no problems. This year I had 2 new style 3W -150 engine, 1 exploded and cost me an airplane. I tinkered with the engines all season and finally gave up. Bolted on a DA-150 and it ran out of the box better than the 3W's ever ran. I'm a DA believer.

I have 2 3w stories,

I bought a used 3w 85. the engine leaked all over. I sent it to cactus avaition and he fixed it for free. Turns out the original owener took it apart and didn't put it back together correctly.

I also bought a 3w 100 used (old style). the ignition went out. Once again, Cactus repaired it for free under warranty.

that is 2 motors that he never sold me that he fixed, for free. that is good service.