Medium or Long Limbs

A question posed to me yesterday at the range by a 'newish' archer. I have a <>28" draw length. What would be the difference between medium limbs (which I recommended) and long limbs (which he has the option of buying used) considering the makeup of materials in modern recurve limbs is fairly uniform. I explained that you would have to compare limbs within the same 'family' as different manufacturers will use different combinations. I suggested he could possibly draw +2lb more with the longer limbs. What do members think?