Personally I would not own another Android. The first smart phone I had was a Droid and it would get slow and require restarting all the time. It would lock up and I'd have to pull the battery to restart it. Terrible. I have had Iphones since. Started with the 4 and now I have a 7. They are much more stable and IMO user friendly.
As far as the Flex on the Smart Link app, it works great for me. A big part of that deal is going to be your connection quality to your local network as well as the internet when you are away from home. If you have a good connection the thing is outstanding. I have used it on numerous times on the road (as a passenger) working SSB and CW. Worth every cent. I also use some of the tools, and I have the logbook, and the dx cluster.
I think you will be happy with the change.
(you can sure tell these guys aren't paying for them)
BUT I do have one of each, a Ipone 8 and a Samsung S8 phone in my pockets and I do really like SmartSDR on the IOS in my pocket but screen is to small for me, BUT on the IPAD I love the SmartSDR APP and it works great .
I use the RCForb App on the Android OS to run my FLEX3000 Remotely which works equally well.
your mileage will vary and this is just my opinion