Jeff,
The only issue I'm aware of with the split cowlings is that the plastic will tend to crack if the bolts are overtightened, and I understand the they've been beefed up on the newer motors, plus they have added a grease fitting to the movable exhaust valve on the 115's. The split cowlings provide great access to the engine and they're easy to remove.
I'm a mechanical engineer, have about 550 hours on my 2007 ETEC that has given excellent service, and from what I can tell, BRP has designed a high quality motor that appears to be extremely well engineered. They are fundamentally very simple motors with a very low tech fuel system, where the HP fuel pump, made by Carter and basically the same one used in cars, only has to put out about 35 psi. It has an extremely sophisticated EMM and fuel injectors, which generate about 600 psi at the cylinder. Like you, I also prefer "Made in the USA", so I looked hard at the Opti. They're also light and good running motors, but they're just as loud as the earlier 2-strokes and the fuel system is more complex with the belt driven air pump, etc.
There is a fellow on the Florida west coast who runs a fuel injector cleaning service that I talked to about cleaning my injectors. He admitted that he's always been a Merc/Yamaha fan, but he said that he was so impressed by design of the E-TEC injectors and their beautiful spray pattern that he repowered his own boat with a 175 E-TEC! If you need more info, this web site is a great source of info:
http://www.etecownersgroup.com/post/...post1277069338
You might PM DonV to ask him about his brothers experience when he replaced a pair of F225's with a pair of 200HO E-TEC's. He seemed to be extremely happy with the new motors!