You pretty much nailed the basics in your question, but I'll answer the best I can. I own both 59's and Seth's, and have played Antiquities.
59's - Definately the tightest of the 3. Tight crisp lows, crisp highs. Some hear these as mid scooped, but it's really just that the lows and highs are crisp...the mids are not boosted and not scooped. Think of a "V" shape on an eq. These are the most agressive of the 3, but still very vintage. In an already bright guitar these can sometimes be a bit harsh, and I sometimes feel the neck is boomy in the lows. I prefer an A2 neck bucker.
Seths - Definately smoother than the 59's. They have an open quality to them, a bit more of a honk in the midrange. I love the bridge, although I did have to pot it to use with my Marshall. The lows are looser, but not in a bad way, and the highs are sweeter. The mids are also more prominent, but not boosted. These are more blanced. I have had the Seths in several guitars, and in two of them I had a hard time getting the clarity I wanted out of the neck position. It always had just a bit of a raw quality that I couldn't dial out. I like that in the bridge, but not in the neck. They are a perfect pair in my 57 RI Goldtop.
Antiquities - Definately the sweetest of the 3 pups. Less honk in the midrange...more sweetness. The bridge still rocks well, and has nice crunch, but in a more polite way. It will handle a bunch of gain, and still stay articulate. I didn't get to spend a bunch of time with the neck pickup, but it reminded me a lot of an Alnico II Pro neck bucker, but with a more airy and open tone. Really nice.
Don't be afraid to mix and match the pups. If you want a really tight, crunchy bridge pup, put in the 59' and mate it with a Seth or Antiquity. What kind of guitar are you going to put these pups in, and what kind of inherent tone does it have? That would make all the difference in my final recommendation.
