I have a M2 compact 20ga and M2 standard 20ga, and hunted both last season.  The compact is my primary gun, however I put a Mesa Tactical pistol grip stock on it.  The full size 26" barrel M2 I set up as a backup gun and just yank off the rib mount red dot after turkey season and use it as my duck gun in the winter. 
For strictly a turkey gun, the compact is great.  For a do-it-all, get the full size. 
If you found that the compact was too short, add a slip on recoil pad and that will grow it by about an inch.  I primarily got the compact for the short barrel, knowing I was going to swap the stock to a pistol grip.