Okay,
Well, the HL10 is not necessarily better than the Deltalite 2510, just different. The Deltalite is about 7dB more sensitive but doesn't have as much xmax. For the same power input (both have the same power rating), the Deltalite will give you a lot more midrange output (where neither driver is excursion-limited). On the low end, you could argue that in the same size box with the same tuning, you will get the same sensitivity. However, you can retune the boxes and end up getting a lot more really low low bass out of the HL10 due to its T/S parameters and its larger xmax.
For bass guitar, I would use the HL10 if you want a smallish box that can go really low. You definitely need power to drive it, though. For more typical bass guitar boxes, the Deltalite could work fine. The 12" version is actually pretty popular for bass guitar, with the lower weight of the neo motor being the main attraction.
The port tuning I gave was arrived at by using the Eminence Designer software which is a stripped down version of Harris Tech Bass Box Pro, I think. I have built one of these boxes and it seems to work as predicted, but I have not actually measured the tuning frequency. The box is up in the 80-100 pound range and lacks handles or wheels, and I haven't moved it very far from the spot where I loaded the drivers in it...
John