I don't have quite an answer for you, because I'm on the same train. I want to buy a laptop and still can't figure out which one should I get. The one you mentioned I couldn't find on Amazon USA, but there's this one: Asus GL502VS-DS71 with the same specs except for the SSD capacity down to 128GB. I suspect yours is from the EU region. The MSI I could find and I'm quite familiar with it.
Basically, for what I read and viewed this last week -and it was a lot, trust me on that- it depends on so many factors that it's finally up to how much money you want to expend. Last night, after 5 hours of research, I believe I may have narrowed it down a bit for my mind's sake.
If you read a lot of forums, or Google for instance the question: 60Hz with G-Sync vs 120Hz without G-Sync you will come across a variety of answers that more or less resume to: if you want a smooth gaming experience, go for 60Hz with G-Sync instead of 120Hz without it -unless you can have both 120Hz AND G-Sync-. But I came across a video on Youtube of a guy that was playing The Witcher 3 at 2 different resolutions -1080p and 1440p- with G-Sync enabled and without G-Sync enabled. This example -for my eyes at least- contradicted the fact that many portray that G-Sync is smoother, since I felt it was smoother without G-Sync enabled. The problem is this particular video does not say which monitor he uses, but I believe it's been recorded directly from the card or something similar. The one thing you can be sure of, is that for everything else besides gaming, 120Hz IS BETTER, and makes all smoother -desktop usage, web browsing, etc-. And 120Hz without G-Sync for gaming, well, I believe you have more problems when the FPS are above the refresh rate, but that's something I have to still find out, and having something push more than 120FPS all the time, you don't even get it on AAA games with a GTX 1070 at High/Ultra. So far, I'm more than confident that I will take the 120Hz without G-Sync road. And I leave you the link to the video: https/youtu.be/4zVujhKbUZ8
And regarding the IPS vs TN panel, it comes across the usage you will give to the machine. If you are heavy on editing video or photos, you should aim for IPS since it's more color accurate, better black/greys/contrast and it's viewing angles are excellent. Otherwise, go for TN if you don't mind some color blending when you don't look directly at the screen. TN has a higher response time and it's ideal for gaming since it almost eliminates ghosting and blurr thanks to 5ms and even some 3ms panels -1ms for some desktop monitors-. Some IPS panels came across that level- at 5ms some of them- but are too high end and cost a lot more. There are some TN panels that market themselves as "IPS like" but don't be fooled, they are high end TN panels with great color accuracy and less color blending, but still not IPS -an IPS like panel is found in the Asus Strix Scar Edition, you can look it up on Amazon US-.
I really hope this helped you, because these are the conclusions I came across after Googling a lot, reading a lot and seeing a lot of videos. I believe I've spent 30 to 40 hours during the last 7 days on this, if not more.
P.D.= I'm thinking of the 120Hz panel because, if in the future, I feel it's not enough for gaming, I can always buy an external monitor. G-Sync is always supported by GTX 10xx cards via DisplayPort 1.2. But for everyday use, the standard 120Hz panel of the laptop itself will be tons better than a 60Hz one. Get my point?
Quick Edit: I just tested low FPS -less than 60- on my 60Hz HP Envy with a 940M and the tearing was worse than with FPS higher than 60. I found one or two posts which say that low FPS on a 120Hz panel the tearing is less noticeable.