The best gear is only useful for a millisecond and not even needed on 99% of the content. Plus this game makes it too easy to catch up to the point that the most efficient way to gear up (provided you don't want/need the gear the small percentage of the time it is useful) is to just wait for the next patch. It's demotivating. Don't want to run Alexander Savage? Just wait until the next patch and you'll be given gear that raiders had to work hard to get. Of course, "work hard" is a little misleading since most of the work in my experience is finding groups that don't completely suck.

In my opinion, the best way to do vertical progression is to have more tiers that stay relevant for a longer period of time. For example:

4.0 Expert dungeons drop i300, Tomes give i320, Raid i340
4.1 Expert dungeons drop i310, Tomes i330, Raid i350

But something like this would require a big overhaul to how things are currently done (e.g. not nerfing raids until more time has passed). Also, I'm not a fan of lockouts. I'd rather have low RNG, at least then I can play at the pace I want.

The effect of the changes I would institute would probably create a larger gap between players, but I see this as a good thing, because people could more easily form groups with people at the same skill level and reaching a certain ilevel would actually feel like an accomplishment.