Quite a few VPS systems run CentOS, which in turn does not include Apache2 in its standard repository. Is there a compelling reason to go with Apache 2.x when it comes to XF hosting or is 1.3.x just fine?
I strongly disagree. Apache 2.2 is very stable and it is faster than apache 1.3 which is very old and not supported any more.Put simply... no.
Apache 2.x has much better support for newer hardware, but overall unless your running an insane spec server or vps... which also in that case you probably would't even be using apache... theres very little point in upgrading.
1.3 is proven stable and has lots of modules and support available for it.
Im not saying it isn't faster or stable. I run Apache 2.2 on my dedi server... im saying for the point of running a xenforo board there is very little reason to upgrade which is what the op asked.I strongly disagree. Apache 2.2 is very stable and it is faster than apache 1.3