The resource manager and enhanced search aren't needed by everyone. The resource manager is more for product downloads and such. I use it, but none of my clients do.
Anyway, personally I like the renewal model. There's less of an outlay for the base software and if you add it up over time, it's about 4 years before XF roughly equals the cost of vB.
Now if you add in mods, I'd place vB and XF on equal footing. Many, many vB mods are premium mods to get all of the features. Granted there are more 'crippled/lite' and free mods for vB, but so far as premium mods go, IMHO XF and vB are about equal.
From my personal standpoint. When I release an add-on for XF it's either going to be free or premium. There will be no 'crippled/lite' mods released.
What about the inferior search function ? Why would they charge for a superior search function when they can include it in their core product, after all, they want to sell a good product, right ? I think anyone who stumble upon the XF search addon/plugin, will say "Why am I buying a search addon that should be part of the core function of XF? Are they giving me a product with a weak search function ?"
Now regarding what you said about addons being on equal footing and the price being the same, that is not true but that is your opinion. I see XF as a starting company applying bad policies and we know that, in order for them to generate more revenue. No one wants to be forced to renew for higher price or lose what he or she already purchased if he or she wants to reduce the renewal price.
XF is allowing coders to sell their addons directly on their site. But that doesn't make their product better, in fact it makes it look inferior because look at their pre-sales forum. You have a new customer curious about XF and he or she asks normally this "I use such and such features on VB, does XF has the same functions?" Most of the answers that appear "Yes, you can do this with addons, there are these addons you buy and these addons you can request for and yes we have these as well" So as a new customer, he or she looks and find himself or herself having to deal with tons of addons just to meet VB default functions + some of vb free mods/addons. You think he or she will switch ? Most probably not.