Many schools teach the Okanagan-type shallow approach, which was used by someone many moons ago and never been questioned since.
It should (in theory, anyway) minimise collective movement for the hover, since your power is already applied, but there's very little margin up your sleeve at the end, and you need to be very aware of your winds, although it does give you a good idea of the level of your site. You are also trying to land at probably the only spot available for miles around, and if you have a problem in a shallow approach, you aren't going to get there.
I generally turn in steep around 60 kts with the disc loaded as much as possible, consistent with descending at about 250 fpm (landing site just forward of the nose). If the blades have some tension on them, they are less likely to be overstressed, and the controls are more responsive. Coming in steeper also means you use less collective and allows you some momentum from gravity if you need to peel away in a hurry, giving you half a a chance of making the site. Certainly more than with a shallow approach.
Also, don't approach straight in to a site, that is with a large lump of mountain directly in front of you - 45 degrees is best so you can peel away. Mountain pilots always have a way out, even after they've lamded!
Phil