There should be no difference in the quality of transmission and reception between 2.4ghz and the 5.8 ranges on the same wireless system.
Where the problems with these units operating on the 2.4 wifi band is all the routers, access points, smart phones and devices, and smart appliances in use today, the likelyhood of interference is greatly increased. Not so much in the 5.8 band, apparently. Several years ago, I had 2 experiences that have me convinced to never use a wifi-frequency-based wireless system. I had a remote mixing system shut down by a Line Six guitar wireless until we did some frequency-shifting and our wifi-based wireless-DMX system shut down 3 wireless units of a national act.
Now before you wifi-based wireless users starting burning me down over this, just save it (like that won't happen anyway...

). I fully realize there's many thousands of these units in service and operating just fine, which is fine with me. I've just had to deal with issues popping up from this units and I've made a choice just like you have.