Biggest issue with 3.0 was its first patch after launch was terrible and slow and then the content within was pretty trashy. If they can smooth that out for 4.0 it'll be fine. i think the patch timings are fine, personally. Allows me to get done what I need to do and take it easy towards the latter half of the patches to play other stuff.
Yeah, the patch timings are fine. They just need to better pace their content. They definitely need to avoid a repeat of Bismarck and Ravana EX.
There's nothing wrong with vertical progression, and there's nothing wrong with making the earlier steps of that progression easier as newer stuff comes out. But there's no reason for entire chunks of content to be skipped.