For me, there's no reason to look anywhere other than Forster-Bonanza, or Redding. You can pay more and get the same thing (Redding) or pay the same and get less (everything else).
I have Forster dies in almost every cartridge I shoot, or will shoot, and have been nothing but pleased with them. In cartridges they didn't have, I went with Redding and have been pleased with them as well. I'm not averse to spending money on good dies. That is not an area to go on the cheap IMHO.
If a guy has nothing but RCBS and is happy with them, who am I to argue? They do make good dies, have fantastic customer service if you ever need it, and their seater does something the sliding sleeve dies won't do. Crimp. I have a .375 H&H seating die, and that's all it is for. Crimping bullets in place. Even though I prefer other dies, a set of RCBS dies is a good choice and it's not money wasted.
Lee's Collet die has a ton of fans, and it should. If Neck sizing your brass is what you want to do, there is no better choice. Problem for me is I don't NS, I FL my brass. I was given 2 sets of Lee's, and can't say I'm impressed with the fit or finish of either of them. Being a machinist, maybe I'm a little too picky, but that's how they feel to me.
Heard a lot of issues with Hornady dies when they came out. Maybe they are better now? Unless you get a killer deal on a Press/Die kit that comes with them, I really see no reason to seek them out seeing as what else is on the market that I'm totally happy with instead.
As for the Micrometer Head, I use them. So they cost more. They are worth it when it comes to convenience. Once you find the depth your are after, just write the setting down in your notes. If you try a different bullet it will need changing of course, but you can always go back easily. Throat erosion is easy to keep track of as well.
