Oooooer! Never thought I'd have the opportunity to correct Dennis Kenyon!!!! (Now I bet I'm wrong anyway)
The 500E I've always flown has the C20R which.......erm.........I think has 450SHP.
If I'm not mistaken, it's the C20B which has 420.
Nevertheless, I chose a Gazelle over a Hughes 500 for several reasons (not just because it has a 650SHP engine!).
Although it's never going to be a pleasant experience in either machine, rear passengers in a 500 are going to have less visibility, and less room. Couple that with the fact that they'll have their luggage on their lap, and that's one of my main reasons for choosing the Gazelle. Secondly, I think the flying characteristics of the Gazelle are superior, with power to spare on the albeit very occasional hot day, with full passengers and fuel. The SAS system is also second to none, with the electric trim system on the 500 a little slow to react during take off and landing.
Also, perhaps more important, is the issue of endurance. Roughly speaking, building in a reasonable reserve, 1.50mins in the 500, against 2.30mins in the Gazelle.
Lastly, although not particularly important, both startup and shutdown are quicker and simpler in the Gazelle.
Oh........and then there's the sound of that engine........
