Definitely full gold. Just don’t overpay: as I’ve mentioned a few times in other threads (whenever someone is contemplating a precious metal Omega), when it comes to gold watches, this is not a brand that holds its value well. You can pay $25k USD at an authorized Omega dealer and as soon as you leave the store, you’ve got a watch that you’d be lucky to sell to another buyer for $12k. You’re much better off buying from a preowned/gray dealer and avoiding that hit. There are many of these on the market in the $11k to 18k range. Just be careful—especially with Japanese listings—to avoid ones on chrono24 that say, in the fine print, “item needs to be procured.” That means they don’t actually have the watch, and they can tie up your money for weeks or months. You want “item is in stock.”
Full gold. You’ll love it. It has a solid weight around your wrist that gives you a secure and assured feeling your watch is right there. It feels comforting. Its gleam will also catch your eye and you’ll be stealing glances at it every so often.
If you are even considering the full gold watch as an option I have to assume that you are not looking for subtlety in this piece. I like subtlety, but if I was considering not being subtle, the full gold would do it.