I'll go on record as saying I like the naming scheme.
Golf has similar things - Titleist has called their drivers 90x or 91x for a number of years (currently 913D2 and 913D3 - 13 is the year and D2/D3 the variant), their irons are currently the 712.MB and so on. Other companies do a mix but almost all involve numbers to signify different things.
D1 fades the most, D4 turns the most. The only real downside is that they'll have to add "L" as in "LD1" or something if they ever make a "longer" driver, and I suppose I might have started at a different number too to prevent issues if they release a driver that fades more than D1? Do you call it D0? Then D-1?
But in general, I like the names. If they keep the naming consistent people won't have to wonder: which fades more - a Hawk or a Raptor? The naming
informs.