Jon,
Very true that it is more pricey. Keep in mind that it also provide the AHR-S which will give you a full gyro driven Artificial Horizon on the iFly 720, tbd on the 700. Also, many ADS-B guys will tell you if your going to get the best bang for your buck and gain the most functionality out of the "2020 ADS-B Out" mandate, get the ADS-B with 978 and 1090 bands, basically dual band. The Mandate is only for "Out" and has nothing to do with "in" or being able to receive it. An ADS-B Transceiver is really the way to go if you want to get the best Traffic coverage.
The short story is that I wouldn't put to much faith in the ADS-B traffic with only a receiver as this time. Your only going to see a very limited picture. The network is being built based on a Ground to Plane and Plane to Plane network functionality. The ADS-B outs there are, the better the coverage. But if you can't receive Plane to Plane, you'll be more in the dark. In that case, I'd just recommend the ADS-B for Weather, not traffic.
I tend to think have the dual band just sets you up for the best possible scenario come 2020, especially if you ever fly in Class B or a Mode C veil. Plane to Plane at lower altitudes will become very handy as we get closer to 2020 and more aircraft have the ADS-B out. It's all a matter of preference and avoiding needing something later when services expand.
As for having to remove the SkyRadar from your wi-fi list, you might contact Ed to make sure you have the latest OS, there were some Wi-Fi fixes to the 720. Either way you go, just be safe and keep your eye outside the cockpit.