Depends on what you mean by "light hiker". If light hiker means small/day pack, then about anything works that fit your feet well. If by light hiker, you mean heavier daypack, backpack, lots of rocks, then different shoe. Alot of people have gone to shoes for all of the above. I'm kind of in that boat. I wear Salomon X Ultra for everything but do have the mid height shoe. Last weekend did a quick overnight in the Smokys with a 40 lb pack ( had fishing stuff and some of the wifes things). I've worn the low top version but discovered recently I need a EE in Salomon. The weekend before we did a shade over 20 miles in a single day with 3200 ft of vertical. No foot issues of any kind on either trip with the X Ultra. Im on my 2nd or 3rd pair. I've also worn my Brooks Cascadia trail running shoes for day hikes. Have done up to 15 miles in a day with them. Zero foot issues.
In summary, it depends on your feet, ankle strength, and terrain. I spend alot of time walking around barefoot. My feet are physically tougher, both skin and soft tissues in the foot from doing it. As a result, I can get away with shoes in most hiking/backpacking situations. If I was off trail in steep, nasty terrain (i.e. rocky, gnarly) I'd move to a short boot. We have alot of rock in the Smokys but nothing like I've been in out west, especially the Winds a couple years back.
Regardless of what you buy, try them on, make sure they fit with the sock system you plan to use. If your choice doesn't work, eBay will yield some return on your investment. In fact I've bought used shoes/boots that were in good condition from ebay when I wanted to try something. In fact bought a pair of Keen Targhee II a couple weeks back. They fit my feet well. I don't plan to hike much in them but do intend to wear them around on crappy days. My normal X Ultra have seen way better days and wanted to try something different.
