I tried 8's for a while years ago..I find the difference between heavy and light strings to be a tonal trade-off, but I actually believe the lighter gauges have a slight edge. While heavier strings sound naturally thick, they often lack sustain and finesse. The lighter gauges provide smoother/more accurate bending, and the high harmonics are more extended and effortless. The only problem I have with light gauge strings is the way a heavy pick causes them to deflect more, making articulation a bit more demanding...
All of this assumes the player has made all the necessary playing-touch and tonal adjustments to maximize the effect of the particular string gauge they have settled on...
Having said this, I believe a great player can make *any* gauge of string sound heavenly, and I have seen numerous demonstrations at either extreme, light or heavy... Pick your Poison!
I loved soloing with them but found riffing difficult.. especially if you hit a string a little too hard and they sharpen for a moment before returning to pitch..
then I switched back to 9's.. that was until I discovered Ernie Ball Hybrid 9's with the thicker wrapped strings..
seemed like the best of both to me..
now that I tune to D-standard, I took the same approach and created my own custom set..
Ernie Ball Power Slinky, but I swap out the 5th and 6th strings with a 40 and a 50
when these are tuned to D-standard they feel like Hybrid 9-and-a-smidge tuned concert..