I actually think about this question a lot, and here’s something to consider reagrding HD combos in general.
When selecting what combo you are going to do off a hit confirm, you need to evaluate many different variables. Some of the key things to look at is pretty obvious, such as how much meter you have when you activate (remember, no building meter during your HD combo!) and how much health your opponent has. But there are also variables that people neglect. Things like how much time is left on the clock, how much meter your opponent has, which character you are doing the HD combo to (point, second, or anchor), and how much health YOU have.
To elaborate, consider that you are on your second character and you’ve landed a full hit confirm. Your opponent is also on his second character with the life lead and no meter, while you have full meter but are close to death (~20% health). Do you go for the full HD combo kill, thus getting to their anchor but at the same time, giving them 3+ and full drive to work with? Or do you opt NOT to do the HD combo, saving your own meter for your anchor? Personally, I would save the meter and do as much damage meterless as possible so my anchor is fully stocked to run it back. But this is where you have to factor in all the different variables. What if you had the life lead? What if your opponent is already sitting on full meter? What if there is very little time left on the clock?
When I think about HD combos, I try not to think solely on how much damage it does. Of course that’s one of the most important aspects of Hd combos, but don’t neglect the other aspects as they are pivitol in the decision making process during your hit confirm.
One last thing to consider… if you are playing against someone of equal skill, both players should be fighting for every inch of space and health by burning EXs. If you can manage to maintain a health AND meter lead for the majority of the match, than you are clearly a better player who should win anyways, regardless of how much damage your HD combo does.