I don't want to repost someone else's post photos, but....I bet Texas Skeeter has comparison photos for you to look at and decide if you'd like Tacti-Cool (18") or Tacti-HELLAcool (14")
I only say hellacool because of the relative exclusivity of having a 14".
I guess intended purpose should be considered. For years the 6+1 Rem 870 was deemed acceptable. Now that the M4 has come around with a 9+1 possibility in the 18"(float a round on carrier) all of a sudden the 14" (5+1 I believe??) is seemingly inadequate!
My $.02, is, if it's for HD and fun, the 14" will suffice. If you're going to do 3-gun, then negative, get the 18".
Either way, in the end, you'll be saving up $$ to purchase the one you don't have.
Best of luck!
May superior training, weapons and tactics keep our Troops safe; domestic and especially abroad! Let Allah sort the dead bad guys out!