I'd still take a phone. Android has limitations as a master device

Sent from my SM-G920W8 using Tapatalk

Go mainstream. Millions can't all be wrong... So if something does break it is easy to fix or replace.
So either Apple or Samsung.
Android gives you more freedom, apple gives you an easier user interface.
If for you the size is ok, get a tablet. 10" is great for the available visual real estate. For Android there are dozens of free offline navigation apps, maps.me / mapswithmee has been mentioned before.

Personal use: Sony Xperia Z5 and Samsung tablet.

Not sure what you mean as I have read of many people travelling with just an Android phone and nothing else.

I take your point, but I have decided to buy the Asus tablet. I looked at a range of Samsung tablets, but the specs seem to fall behind the Asus tablet. I have also read a few articles directly bench marking the Asus tablet with a number of Samsung tablets. As for the iPad, it's hardware does not seem significantly better than the Asus tablet, also no internal card slot is a deal breaker. In light of this I would find it very hard to justify the cost.

Despite my thinking, I do acknowledge it may not be wise to rely on one device. As such I plan to take a very cheap Android phone (probably a few years old off ebay) as a backup in case the tablet breaks. But I hope with a waterproof / shock proof case the tablet will be fine.

Probably thinking of USB capabilities ... get one that has USB OTG so it can act as a master on the USB buss .. some as just 'slaves' on the USB buss meaning they cannot read stuff off the USB buss .. they can only be read over the USB buss.

Just my two cents but buyer beware. The build quality of the ASUS stuff isn't great. Sure, for the price you get a great spec and for sitting at home watching movies and playing Candy Crush that's all well and good - if it dies it's no great loss, you can send it in for a warranty repair.

Out in Whereveristan, when you are both putting greater physical demands on it and relying on it for navigation failure is probably a touch more inconvenient! I'd be going for a proven premium brand with a huge worldwide presence and known reliability, like Samsung.

Anything but a Windows platform only allows you apps, which by design are watered down versions of "desktop" software.
If you want to go of the beaten tell you may look into some GIS applications to get the base data into a phone or tablet which you can't do on any of the tablet options other than Windows.
In other words, an Android or iOS tablet cross over with a phone and don't complement.

Sent from my SM-G920W8 using Tapatalk

I sold my Garmin and bought an Android smartphone (Motorola Moto g 2/3gen waterproof). I'm very pleased with that decision. I use it with openstreet map OSMand (you can even download Wikipedia text integrated with the maps). I have the same software on my tablet. For a longer trip I'd buy a DeLorme Inreach for emergency satellite communication anywhere.

The phone is fantastic. One small device is GPS, phone, camera, watch, torch, notepad, Kindle, guidebook etc. Apart from the phone, it works totally offline (translation and sign readers are also available online). Because it does all that, I always have it with me.

I should be nervous about reliance on one device, and depending on the situation, I'll always have some "what if" plans.