I really don't like the idea of using slow release fert on fields due to not getting that initial heavy bump. Anyone have experience using 18-12-12 slow release and was it worth the extra cost?

I used it last year on like 35-2-10? It was for oats. Worked great. I was very pleased with it.

New to me but have heard it advertised as of late. Something to do with the nitrogen being released slowly.

Slow release has It's place. It mostly used in the turf and ornamental markets and some special ag applications. Question that you need to ask is What percentage of the nitrogen is s/r and of that percentage how many days does it release.
There are a bunch of different releases but the most common are 45 day, 90 day, 120, and ,180 day. They get more expensive as the days increase. A lot of your basic s/r grades you see will be made with a 45 day release polymer coated urea or something similar in a sulfur coated. These are not really giving you much more time than your other nitrogens would stay in the soil and available. Where they help are they help with N loss during that time. Kinda sorta comparible to a stabilizer

Yea that's my biggest problem with it. We use it on turf to keep it green but not have the aggressive growth you would with ag fert.

17-17-17.

yes in turf you want it to stay green and pretty bunt not growing a foot in 2 weeks lol. For food plots I wouldn't do it due to money. You can come back and hit it another shot of regular N for less. Now then if money was no problem you could go in with something like a 50%slow release made with a 120 day product and make one application. But you would need to put a lot out so that you would have enough N coming from the other 50% that's not s/r. To really get it going since there is a lot of pressure on it