I have a Surface Pro 1 and a MBP. I've purchased 2 SP4s throughout dental school and then returned them both.
The Surface is a cool idea, but honestly it's just not all that practical. The only reason to get a Surface would be for taking handwritten notes. However, my personal experience is that lectures move too quickly to take handwritten notes. I took handwritten notes on a SP1 for the last couple of years before dental school and would love to continue to do that, but there just isn't enough time.
My other main issue with the Surface is poor battery life and it just not being very reliable.
- Don't put your Surface to sleep when putting it in your bag (turn it off), they love to do some sort of background processing and use up all of their charge. It's a problem they've had since the very first one was released years ago.
- Then you have the pen which will often not be recognized, until its drivers are restarted.
- Windows loves to decide that you must install updates and restart your computer right now. Who honestly thought it was a good idea to not have any user friendly way to stop an update from installing while the computer is actively being used?
- You think it's great to have a tablet that can run any computer program, but you'll quickly realize that the experience using most of them sucks. Some won't respond to pen input. Things will be minuscule and hard to hit with your finger.
- Finally realize that the Surface Pros are not repairable at all. If your battery is wearing out, MS will let you trade in for a refurbished unit for hundreds of dollars - at a small discount from just purchasing a new unit on sale. People constantly complain about the repairability of Apple products, but honestly most of them are pretty easy to do common repairs on. Apple will do a battery swap on their devices for about $100 at any Apple Store.
- Also we deal with a lot of PDFs and honestly the experience dealing with large PDFs on Windows is not very good.
As for an iPad Pro - again there is not enough time to handwrite notes. I also find it hard to justify the price when the Surface Pro is more capable and available for so much cheaper, but again it has downsides.
In the end: I'd go with a MacBook, maybe some other "regular" laptop if you don't want to use Mac OS for some reason.
Edit: Something else to add, the mic on the Surface Pro 4 is terrible. I have all of my notes synced up with an audio recording of the lecture, the poor quality of the recordings from my Surface Pros really bothered me.
But related suggestion: Use MS OneNote for your notes and record audio while taking them. It syncs your notes with the lecturer's audio. That way you can easily review a specific part of the lecture when studying. Also your notes will be synced on MS's cloud service, OneDrive, and be available from any device. I have all my notes on various computers, accessible to be on school computers, on my phone, etc. OneNote is free and you get an unlimited amount of space from MS with your school email address.
Another stupid decision by MS with this though: OneNote for Mac records MP3s, OneNote for Windows records in WMA. They don't have the capability of playing back audio that was recorded on the other platform. The iOS version can only playback MP3 as well and cannot record or playback while doing anything else.