KBY,
Welcome aboard! I have a 24" Stainless Steel/Composite Huntsman and it carries better than any deer rig I have. It really is balanced well with a 3-9x42 S&W scope mounted. If you are walking back in 1 mile, you will probably like the lighter weight of the 24". The 24" will be a tad faster in the handling dept also. You can get up to 100gr of powder to burn in it also, which is more than enough to do the job.
If you have Magnumitis and think you will need more than 100gr of powder then you will want the extra 2" of tube. Like MSP Ret says go handle both and see which one you like, the deer will never know the difference. Bottom line, you are the one who will be carrying it.