You will have a hard time finding apps for the Surface Pro. Hopefully yours you can load whatever software you like. Some of the cheaper ones can only load app from the Microsoft App store which is very limiting. This app has been around forever. I haven't used it in 10 years.
Official OziExplorer Web Site - GPS Mapping Software for Tracking and Navigation. Supports Garmin, Magellan, Lowrance and GPS
As for Apple vs Android. Nearly everyone I know has been happy with switching to Apple. Unless you are a developer, like tweaking stuff , and know how to do custom installs etc you don't really need to presumed "flexibility" of an Android device. The user interface is so much better on Apple. Gaia is better in iOS.
Apples "locking down" of its devices makes them more secure. It also gives developers better tools to make great looking apps. Android suffers from similar issues as Windows. It "works" on any device. All types of screen sizes, cpus, ram, and so on. This makes is way more difficult for developers to build nice looking apps. Anyway, I probably won't change anyones mind on that subject. I have an Android phone as a back up, have owned a Nexus tablet and neither has ever made me want to switch to Android.
But as mentioned buy what you want to buy.