storm eagles are a fluff commitment.
There are 'better' flyers than it for tank hunting (xiphon intterceptor) or infantry removal (fire raptor) and 'crash and burn' makes for a risky transport for 20 man squads along with the vulnerability of being a valid target for
everything when it has disembarked it's troops.
Those things accepted, it looks fething cool,
PoTMS allows firing the vengeance launcher every time regardless of jink, you can fit a full tactical squad in it and
most importantly - You get to put on 'ride of the valkyrie' when bringing it on. (loudness determined by number of storm eagles coming on at once)
Air-Cav
always has the best theme music.
I tend to kit mine very expensively:
TL lascannons on the wings,
TL multi-melta on the front so it can do some basic anti-tank stuff and lay two large templates on a seperate infantry unit at the same time.