2007 150 Opti…LEMON that Mercury got me out of and gave me a 175 ProXS replacement for my troubles. 2008 175 ProXS Great motor first 100 hours. After that it needed coils, more coils, problems with poppet valve caused me several trips to dealer (not a manufacturer issue), finally had to have an entire wire harness replaced, 100 hour routine maintenance was expensive, spark plugs were about 20.00 each. Current Mercury 2008 225 Opti (standard Opti) Knock on wood not one issue to date, 88 hours with one water pump impeller changed. Estimated cost on 100 hour service is 400+/- depending on reeds. If reeds are cracked price will jump about 600.00 more. The standard Opti still uses metal reeds.
The thing that I notice that I do now that I didn't with my first is always waiting until the engine warms to 120 before going on plane. and watching the temp to make sure thermostats are working properly.