For this price I would go for the Acer E5-575-33BM.
This Dell uses a very limiting 1366x768-resolution display. 1366x768 resolution doesn't let you fit much onscreen. It doesn't let you properly take advantage of the size of a 15.6" display, it just makes everything onscreen large. This kind of a difference is likely to affect how nice your computer is to use more than the differences between most other specs.
If you want the Acer to match the 8GB RAM in the Dell, get an extra 4GB RAM stick for $25 to install alongside the existing 4GB. Doesn't impact your warranty and is easy to install and take back out again. And if you're worried about CPU performance, the i3 beats the A9 anyway.
I think this is a better choice at ~$700 https://www.amazon.com/Dell-15-6-Inch-Quad-Core-i5-6300HQ-Processor/dp/B015PYYDMQ/
GTX 960M instead of 940MX, IPS 1080p display instead of a poor quality TN (not a good TN like some desktop monitors), same 256GB SSD.
I wouldn't really recommend this one, tbh.
The reason I don't think it's worth it is because of its 1366x768 display. 1366x768 resolution doesn't let you fit much onscreen, and such a large screen it makes everything onscreen rather large. The display, even if less considered by some people, actually tends to make a lot more of a difference than most other specs for how nice a computer is to use. $429 is in price territory where 1920x1080 starts to become an option, and I think it's one of the most important things to get.
The 8GB RAM might make it look like an attractive option, but it doesn't really make much sense to buy a computer for its RAM. RAM is cheap and easy to upgrade, and the difference between, say, 4GB and 8GB, won't likely make near as much difference as other things for most use.
At this price point, the laptops to choose from for general use are these:
Both have 1920x1080 resolution displays which will significantly improve screen realestate. The Dell should have a better quality display + touch, whereas the Acer is cheaper.