any one used these mechanicals? if so how did it go for you?

I've shot the following with these heads: 1 deer, several turkeys, a coyote, pigs, armadillos,squirrels, rabbits, geese... everything died for sure. I personally shoot Slick Tricks because I can't find any advantage to shooting mech's other than large cutting diameter. I'll still shoot them for turkeys, and I carry them in my quiver for any of those random animals. I personally feel that their blades are very weak, I won't shoot them for anything except for smaller animals.

do they shoot like field tips?

I've tested and shot a ton of Mechanical and fixed heads. One thing I can say for-certain, Eastman heads are junk. Stick with a company that specializes in the design, development, and manufacturing of their heads.

NAP, WASP, PISTON-POINT, and RAGE to name a few....

these heads used to be sold under a different name, i shot a buck with them and one year cause i didnt get my new steelheads in the mail before opening day and it worked great but of the six i bought 2 had 1 blade open stiffly and i just put them in box for messing with the other thing is get a sharpener for them theyll cut but they are not razor sharp. if your on a budget and want field tip accuracy these are decent heads honestly and my brother shot a deer last year with the onesi had left over from the previous year no problems. like i said sharpen them up and make sure they open freely.

I will 2nd that the Eastman heads are JUNK! There are a lot of good choices out there. You just have to keep in mind a few things, what are you hunting, how far your going to be shooting, the total Kinetic energy for you bow, and what features do I really want in a broadhead? You can check out my website and get a lot of good free info.
www.broadheadtests.com

thks!