I have used the Pub in a bitter (tasted delicious going into the keg) and pitched the Independence in a pale ale today.
The price point isn't an issue for me -- double the cell count without double the cost of a Wyeast smack pack. I don't re-pitch or harvest either, so cost is cost regardless of company. The pouches are easier to open with slippery Starsan hands than the swollen Wyeast packs. I like that. Lastly, but not leastly, I pitched it today at 17 celsius at 1pm; it had taken off full bore in the airlock by 4:30pm. Shortest lag time in my years of brewing. Cell count, I guess.
I love Wyeast's selection and have been very happy with their product over the years. I will continue to use Wyeast, but find the no starter part of Imperial to be a big selling point. Am not an devotee of either brand, but having selection is always a good thing.