1: the difference is minimun, you should didnt note a difference.
2: the MX150 is WAY better than the UHD 620, the MX150 is a portable GT 1030 (whit more clock). CSGO in the MX150 is much better and you should be able to play more games.
3: for 1000$ you can get a Coffe lake (8th gen) i7 whit a 940MX (4GB VRAM) and many more features.
Here is the best minus 1000 dollar laptop in Amazon for me, from HP: https/www.amazon.com/HP-Pavilion-Keyboard-Flagship-Quad-Core/dp/B078436XZS/ref=sr_1_8?ie=UTF8&qid=1519772589&sr=8-8&keywords=i7+8550u+laptop+hp
It has a i7, 940MX, retroiluminated KB and much storage,
Final conclussion between that the two Acer: go fot the 15.6 Swift 3, it has a better display and panel and is more powerful.
Greetings and sorry for bad english
EXTRA: a 1000$ laptop whit almost no difference: https