After the prepatch I decided to dust off my horde mage and try running a couple of dungeons as fire to get a feel for the new changes. It's not a spec I have touched much for the run of several expansions now and was hoping that maybe they had alleviated my issues with it. But nope, I still find fire to be thoroughly unenjoyable and a constant exercise in frustration, and I suppose I should just resign myself to the fact that this is how the spec is going to be forever now.
I've surmised that the main thing making the spec feel so aggravating is the way the hot streak mechanic works. More specifically, how it requires you to get 2 crits in a row in order to actually trigger it for real, and thus if you don't get that second crit off after you're halfway through, it just resets which is the worst damn feeling in the world. Those downtime moments when you don't have any fire blast charges available and you're just resigned to spamming fireballs and praying for enough rng to not reset the counter has such a profound psychological effect on how the gameplay feels.
What makes this such a bummer for me is how my main point of reference for the spec is always going to be how it worked in Cataclysm a decade ago, where IIRC hot streak worked nothing like this. This was when I first started playing fire mage and was basically the most fun time I ever had playing mage as a whole (I've heard anecdotes that fire was even better in WotLK and I suppose I'll just have to take their word for it). All I can remember from the switch to MoP was this feeling of complete alienation when trying the revised fire spec, and I think this is also when the 2 stack hot streak mechanic was first introduced.