I've used a HR link 7 on alto for 15 years-it's fine on alto and you can hear it on my youtube stuff below. I've used it for Jazz, lead alto, 20's bands, Salsa, Soul-even some classical work. I know other players who use them too. Funny enough though, I've moved back to the Meyer 5 I used as a young student in the last month or so and I'm really enjoying it.
I find that on a MkVI like mine, the built in resistance of the horn means a smaller mouthpiece helps the note to speak more instantly. There's a feeling of being able to play faster using my Meyer compared to the link. Charles McPherson mentioned that about Selmers in an interview and I think it's true. I also like the way I can relax my throat and project to the back of a hall with the Meyer. If you've been playing less than 3-4 years switching to a Link 7 might mean you get a habit of biting-learning to relax the throat can take longer than that.
That said, there's something very special about my Link and they're more versatile than many people give them credit for.
Jamie