I'm also driving myself mad trying to decide what to do !!
I've been a Pronto user for about 8 years, starting with the 3000 and then a 3500. About 12 months ago when I started on the (now epic saga) building of a new house I decided to stick with Pronto as I love the combo of touch screen and hard buttons, so I dropped a large chunk of change on one of the Pronto Pro 9600s. And of course about one month later Philips annouced it was dropping the entire Pronto range.
One of the most important things for me was to get back to one single control panel in the theatre, as for some years I've been using Windows Media Centre, with a wireless mouse and small LCD screen, to navigate my music collection. The new house has Sonos throughout including a feed into the theatre processor, so I wanted something that could also control Sonos. Sonos control is available on the Pronto and that also factored into my decision. I also intend to use the Pronto's two way capabilities. My integrator assures me that they will support the Pronto for many years, so I'm not overly concerned about that.
Now on the iRule side, I know I can get an iPad app for Sonos, and I assume it's not a problem to jump back and forth between iRule and the Sonos app; iRule is about to introduce two way, so that pretty much leaves me with no hard buttons as the only problem ... but I think that's a big one.
What to do ??? Oh ... the pain !!