The shell is exactly the same just a different cover, they both feature the active bootboard, drop kick is a 4 flex tounge (incredibly soft), hot dogger 6 flex tounge (soft/medium), drop kick plastic buckles, hot dogger aluminium buckles.
Personally I would go with a the hit doggers as they have metal buckles which wont break like the plastic ones, if you do find the flex to stiff (which I doubt you will) you can allways swap the tounge for a 4 flex toungue
A friend of mine tried both and ended up going with the Drop Kick. The liner just felt better to him - it's slightly thinner, and he has a very tall foot, so he got a better fit in the Drop Kick.
If you can afford both, go with the one that fits better. Actually, screw that, never go boot shopping with a budget at the top of your priorities.