I have the 590, 595, XT and XT2. They all have issues out of the box but with know-how they are excellent devices and will give you what you want.
The XT1 and XT2 rely on BT for their connections but they work well with BT headsets and with phones.
The XT3 is unknown to me, but I have been following threads on ZumoUserForums and so far there is nothing that makes me want to update. Some of the issues with the XT2 have been carried over to the XT3.
It is the XT2 that I have on my bike/trike. The (very big) issues that we unearthed on ALL XTs with the imported GPX file (from any mapping software) we have found solutions for and now on the road, they are reliable, screen is bright, and I have no problems.
I use my XT2 with android phone and Cardo Packtalk edge. I also have the handlebar controller. The Tread app which Garmin developed as a way of getting routes into the XT2 using BT is not as reliable as I would have hoped. It alters my routes during creation and during the synch process - so I still transfer routes to the SD card using traditional methods. The best solution for the XTs has been a program developed by FrankB on zumouserforums - called TripManager. It requires a PC and a USB cable but it bypasses Garmin’s import process which often changes my routes, and makes the route behave ‘properly’.
The Tread App can still be used to relay traffic info, weather info, provide up ahead info eg fuel, attractions, hotels etc.
Messages, emails, texts and other alerts can be relayed to the Zumo screen - or not. Up to you.
The XTs all have an excellent mp3 player built in. With so much relying on BT, I have found music relayed from the phone to be less than reliable, so I don’t bother with that. But the voice commands hey Google can be relayed to the phone from the ZUMO screen if required.
I have a series of XT2 screen displays in an interactive mock up here.
https://zumouserforums.co.uk/XT2-P309