Double din head units

All I can say is do your research. I knew nothing about the damn things when I leapt in and got a Sony put in. I can't recall the model, but cost about $500 at SuperCheap.
The one thing it does do well is the reversing camera.
It only comes with one USB slot, so plugging your phone in whilst listening to music off a USB stick isn't really on the cards. You CAN use a USB hub, but it is fussy which order tasks are started for them to keep going.
Android Auto is highly overrated, in my view. The only navigators you can use are Google Maps and Waze, neither of which particularly excite me. Every time you stop for a break, you have to remember to allow the damn phone to communicate with the headunit when restarting to continue your route if using features off the phone.

The bluetooth connection with the phone is extremely problematic, to the point where hands-free phone is not viable. My wife and I both have Huawei GR7 2017's, and I don't know if the fault is the headunit, or the phones.

Now there are Android units that are fully Android, with the apps running on the headunit, not the attached phone. I strongly suspect that would have been more suitable for me.

Everyone calls removal of the OE head unit and replacement with something else, an Upgrade. What is wrong with the original unit? Sometimes they are better in some functions but sometimes it is a downgrade in what they do. No CD and no nav means to me, why bother.
Yes, look at what you really need but I prefer to have a unit which doesn't rely on a phone or tablet for anything, maybe calls.
Do you tow anything? If so a dedicated screen, and reverse camera can be on vehicle rear and also able to switch to van rear camera, that is essential for me.

I replaced my unit, now JVC not too costly, because the CD player failed and it didn't have a USB input for any music, other than that the performance was adequate.

What budget is acceptable? because there is a multitude of offerings which will do your head in if really searching for the pinnacle at lowest cost.
Radio reception if important to you, the specs must be understood and especially looked at for sensitivity of receiver , both AM and FM. Many modern units are not much good, whereas a radio from earlier vehicles were far better in that regard. Fujitsu Ten for instance in my old Landcruiser far exceeds modern radios. Just not built like they used to be because people want connectivity over radio performance in a modern world. Features and reception sensitivity might be the decider for you, brands are brands to me. Most are designed for LH Drive vehicles anyway with vitals on the wrong side of the screen/facia, some centralized though. If short arms then that may be an issue.

Look up Digoptions.

They do a variety of models to suit a range of vehicles.

My Prado's unit is terrific.

bill

Thanks everyone for the replies.
I have settled on the Alpine ILX-W650E head unit and alpine speakers throughout. Installed it myself and included a module to keep the steering wheel controls. Took a full day to run new cables and clean everything up. Pretty happy with the end result.
I have managed to wire up the camera so that it comes on during reversing AND on preference whilst towing. Just so happens to have android auto - I dont rate it that much and would only be good whilst in phone reception of the metro areas or larger towns.
It still surprises me how much a new head unit and new speakers makes for a better crisper sound.
Thanks everyone for your input.