I have been playing the CB's since they first came out.  I would not even think about playing anything else.  The feel and workability of these irons are the best.

I love my Titleist 712 mb. I played the 710 cb before getting the mb last year. I just had to have the satin finish, lol. I like other manufacturers a lot to but i have always been a Titleist guy. My buddy plays the mp 69 and they look and feel great to me also. He is only had them a few weeks and he is having a little trouble finding the sweet spot consistently at a 10 handicap, totally different results than he was getting inside a fitting bay. Always demo outside when possible.  You need to be atleast an avg ball striker  to game Titleist 712 series or mp series.  Some irons are a little more upright than Titleist so keep that in mind.  Switching to a blade, 3 years ago, was the best thing i have ever done. Love the looks the workability and the feedback. Days that your not hitting it all that good you will lose distance but the days that your hitting it good there is nothing like swinging a blade.

Are the 712 mbs a soft feel, or more of a solid feel?

To me they feel both. Shots hit out of  the middle of the face feel nice and soft and to me that's a solid feel. Miz feel good to though. You can't beat the classic look of the mbs though then you put a satin finish on it and omg, she's a beaut clark. 

What's the difference between soft and solid feel in irons?

As far as the blade category, miz and titleist are the highest in quality in my opinion. I find that the satin finish on the titleist 712 is a really nice touch though.

I currently have the mp62 irons and love em. Ive tried the both irons your talking about and feel that they are a good iron but they also feel harder than mp's. I went and tried the new mp64 with the c-taper shaft and my x-100 shaft loved the 64s better with both shafts and really loved the c-taper, lower ball flight and better feel. I dont think I will ever venture away from mp's, but i will tell you i love my Titliest 910 d3 and F 3w.

i have had the 704 cb since they came out.  these irons have allowed me with practice to lower my hadicap to a 2.  since purchasing these irons i have scored career low rounds with a low of 66 this year.  i just recently purchased the new 712 cb irons but have not been able to hit them as winter is now here.  waiting for a 50 degree plus day to bring them out.  i love the feel desing and the ability to work the ball with titleist irons.  will never play a different iron.