When LEDs first came along I hated them. Flickering, bad color spectrum, bad bases. They've gotten a lot better over the intervening decade, where I will use them in the backboxes. I haven't made the leap yet onto the playfield, but just from the backboxes the heat difference is night and day.
The directionality doesn't come into play as much as I thought it would - the earliest ones I used did, there's some spotlighting on those games, but the latest ones with a diffusing dome are great.