If it's just one station, or two close together, and both are UHF, I'd go with the 91XG if you can swing it. The dB8 presents a big wind load, and if you don't need VHF, it's just a liability, unless you get more ice storms than wind storms. The long beam on a 91XG (it's not a Yagi, it's a log-periodic) makes it susceptible to ice buildup in freezing rain, which the dB8 has less trouble with.
Another option is the CS-4, which is a LOT smaller than the dB8, but performs similarly. This is still assuming that ice is a bigger problem than wind, and you're not gunning for a VHF transmitter.