Main difference I see between the red spin-milled 54-11 and 60-07 vs the SM4 is the sole grinds. The red ones had full soles. The SM4 wedges from 46-52 have full soles. The red spin-milled may not be legal for college golf. I have the Spin-Milled c-c 50-08, 54-11 and 62-07. Same sole grinds as red spin-milled but USGA legal grooves. I have more of a preference for full sole wedges and these 3 do what I want to do. I'm not really a fan of composite grind wedges (I had Cleveland CG15 DSG 58 and 64 and Vokey 64-07) since their biggest limitation is hitting off a tight lie. I like the 62-07 over the 60-07 and 64-07 because I can do more with it (soft and hard short greenside bunkers, grassy and tight lies close in and the ability to drop the ball on a dime). I have my 50-08 and 54-11 bent 1* more lofted and they do a LOT. What you may want to do is take a couple demo wedges (Spin Milled c-c and SM4) with the same loft and bounce and do a side-by-side acid test.

 

The "red" Spin Milled wedges have the "old grooves", and may/may not, conform to the type of tournament you're playing in. They offer medium trajectory with high spin. The SM4 wedges are conforming and have many various loft/bounce/grind, options to suit your game. Maximum spin with lower launch angles. 

 

If you can find an authorized Titleist fitter, I highly suggest a visit to help determine the best setup (old grooves/new grooves, etc.) for your game.