Mizuno mp 29 vs Titleist 690 mb vs. Mizuno T-Zoid Pro

[akim1220]

I have been playing golf off and on for about 15 years recreationally.  Although I have been playing for a while, my small knowledge of golf is only what's done on the golf course.  As far as equipment I am pretty much a beginner.  My first set of irons were a hand me down from my father which were the Mizuno T-Zoid Pro's.  I've been using this set until 2 weeks ago where I got a set of the mp29's and the 690 mb's.  I plan to get back into golf (go out to the course at least once or twice a month) and testing out which set I like the best.  I have been going to the range testing out all 3 and cannot seem to easily pick one.  One day I will hit with one set better than the others so it's pretty much a toss up.  Found this website and hopefully will be able to get some help from the members on this site picking the best set of irons for me.  What are the things I should be looking for when choosing a set of iron?  Out of the 3 sets, what advantages & disadvantages comes with each?  What skill level is each set used for? Which is most forgiving? Which has better results? Does type of shaft play a major factor (zoid - S, mp29 & 690mb - R)? How would you rate the 3?