It's not easy to elaborate it in this regard.
Brief to say, metal outer barrel not only LOOKs but also FEELs better than plastic outer barrel!
It's controversial that metal outer barrel does much more wear and tear to the other parts. In my opinion, rather than attributing this issue to metal outer barrel, why not taking the other parts into account. If the other parts are strong and hard enough, why does this unilateral wear and tear occur?! Needless to say airsoft gun, real one(even any mechanical equipment) does wear and tear. The problem is not at wear and tear itself, it should be at the balance of wear and tear.
Because of the unilateral wear and tear, the steel outer barrel should NOT be the best choice for this airsoft aluminum slide. Aluminum outer barrel is good enough, especially the 7075/6061 aluminum CNC slide and outer barrel set. But it's kinda expensive and hard to find in US.
Personally, if you are only a CQB fan, the original plastic outer barrel should be OK and it's not necessary to spend over 50 bucks for this steel outer barrel. If you want your M93r II looks and feels better, this steel outer barrel is the only choice here. When you upgrade it, your M93r II has fully licensed trademarks(except for the KWA trademark) and is full metal-- that's really I want it to be, and you?!
By the way, I like KWA products but the trademark and plastic outer barrel!
Edited by Billy1788, 04 August 2013 - 12:21 PM.