If I were in your situation I would chose the OD vest. OD works in a large variety of environments, and as a solid colour it goes well with many camouflage patterns. After all, Olive Drab has been used by many countries soldiers for a very long time, and only in the last 20/30 years has the solid OD been slowly phased out for newer camo patterns.
As far as running multiple sets of camo BDU's/ACU's/Combats, many people have two or more sets. This is because most skirmishes have their teams separated into a green team and a tan team. It is also because the colour of our environment tends to change on a regular basis, and most people like to change their camouflage accordingly so they blend into their surroundings more effectively.
I personally run 3 camo patterns which I chose depending on the season, and whether green or tan team needs an extra guy. I currently have a set of A-TACS AU, A-TACS FG and Multicam in my closet. A-TACS AU is a very obvious tan, and A-TACS FG is very green in nature. Multicam is a in the middle pattern as it has both green and tan in it. However, people who run games tend to put Multicam on the tan side as it does have a tan/brown base. Although it is not uncommon to use the guys decked out in their Multicams as a tiebreaker when a lot of guys in green show up and very few in tan come, or vise versa.
In the end, you can have the best of both worlds. You can use the UCP pattern as a base under your OD vest when you are in a UCP-friendly environment. But, because you have an OD vest you won't be limited to just UCP. You can freely run any number of patterns that you wish to use. The sky's the limit... Assuming your pocket is as deep as the sky is high.
NSWDG Enthusiast, Milsim Junkie, Tactical Tailor, Kit Calibrator.
The rants & ramblings of an everyday Weekend Warrior.
Last edited by hot_shot under fire; January 30th, 2013 at 14:42..