Thanks for the explanation Michael, it's good to understand that it was a choice based off which product Unleashed customers were most likely to be interested in, not a sign that the R730's fate is sealed.
In terms of differences between Solo and ZD/SZ R730, the biggest dealbreaker I personally saw with Solo was the lack of DFS channel support. I think DFS channels in the context of a 802.11ac+ AP is a big deal, since in the US there's no contiguous 160MHz channels and only 1 80p80 channel without DFS (and ironically home / small business deployments are likely where one can use these wide channels effectively). Plus the special channel 144 in the US tends to be the cleanest 802.11ac channel since only .ac-capable clients have support for it.
Other than that I like Unleashed because other than SZ, Unleashed has the next best resiliency against single point of failure. And while Mesh isn't supported on R730 yet, one day I do hope to use Mesh with R730.
To play devil's advocate, I've used wireless solutions from many different vendors. One of the most unique things about Ruckus's AP's is that the same hardware works with a variety of controller schemes. Nobody else offers that. Between the 4 Ruckus installations I manage, I've bought dozens of APs and almost all of them have ended up running a different kind of firmware due to my needs changing in unforeseen ways. It still is a big selling point for Ruckus that you don't have to set any network architecture decisions in stone when buying AP's.