covered slip or uncovered rack?

[Veg]

Here's a good one for discussion... We've got to options to keep our relatively new I/O cruiser, both for roughly the same price. It has twin volvo 5.7Gi's with neutrasalt. I've heard a lot about not keeping I/O's in saltwater, and yet I've seen many people around here who do it and don't have any problems. I've also heard the sun is a boat's worst enemy... So share your knowledge.

1. Covered wet slip. No direct sun!!!. No need for full boat cover. Plus marina dock life. Would need to get bottom and drives painted, and who knows how many haul-outs and maintenance? Would have to do onboard flushing...

2. Uncovered outdoor rack. No bottom paint, outdrives out of water. Flushed every time coming out. Boat exposed to elements/sun. Boat has cockpit cover but most of boat would be exposed unless full custom cover was made (for a 33' boat???)... Or regular application of a 'fiberglass sunblock'?

Now, I know a covered dry stack would be best but the cost is out of this world ... Please share your opinions including those of you that have had your I/O's in saltwater and those that have had a boat on an uncovered rack. Some specifics regarding what I should expect in each scenario would be appreciated.