Although clan wars is 'safer' I've always preferred the wilderness over it. Why? Because it's more fun in my opinion. Most of the time you don't know who you're going to run in at what location (guess it's different now with every clan having a ton of leaks and spies). The zones aren't limited in the wilderness, and can change at any given time. I just prefer the thrill of the wilderness, the thrill of possibly losing items, the thrill of dealing with one or more rival clans and the thrill of dealing with clans with more opts. There is simply put more diversity in the wilderness. A clan needs to be truly organised in the wilderness to have good weekend trips. But pking/clanning in the wilderness has changed drastically. It's not as fun anymore from what I've experienced due to all the crashing and teleporting.
I've never been a fan of P2P clanning, and while I acknowledge that skill plays a very huge part in p2p, I do believe items and money play a big part as well in P2P CW. If you don't have the items or stats you're pretty much going to lose vs a clan that has better averages and gear, even if your clanmembers have decent-good skills. In the wilderness you won't bring your best gear in P2P, making fights more balanced. F2P (cw) is more fun in my opinion, everybody has the same items, so skill and stats play a bigger role in an even opted fight. The basics of F2P are fun due to its simplicity. Sometimes less is more.