I got a 7490 recently. Battery life completely depends on your power plan and display brightness. I've done my best to optimize mine when not plugged in. I get about 10 hours light usage and battery saver turned on, but I've also modified the BIOS to re-enable undervolting.

I run with passive cooling on battery now and I repasted the CPU with MX5. Runs about 35C.

When plugged in on max performance, it gets quite hot on the bottom and the fan kicks on at unexpected times, even if I'm not doing anything intensive. The heatsink is weedy and the fan is ridiculously tiny. You should absolutely repaste with the best thermal paste you can afford; maybe even Kryonaut Extreme or such. When I removed the heatsink on mine, the stock paste was all dried up like cake.

I upgraded from a T440s. I prefer the keyboard on the Thinkpad, but the 7490 keyboard is OK. The touchpad doesn't scroll up and down the same way (doesn't travel as far with one swipe as I was used to), which is down to the Microsoft Precision drivers. I reduced the friction and inertia settings to minimum to compensate.

Overall I'd say it's a good laptop if you find it in good condition and at a good price. It's also easy to service. The worst thing about it is that the speakers are crap; the T440s had lame speakers but they go a lot louder. I removed the Waves stuff from mine which Dell forces you to install by default.

It's probably the only Latitude I would consider getting - the newer ones aren't as easy to service and upgrade, and I like having the trackpoint and trackpoint buttons, which they removed after this one, along with the LAN port, I think.

If you also consider newer laptops, battery life and performance goes up, of course, along with the price, but there are some other bargains out there, e.g. HP 845 G7 with Ryzen.

I hope my answer is still for you because I found your thread after 11 days.

I upgraded my WiFi card from Intel 8265 to Intel 9260.

Maybe you should try Intel AX200 for future proofing. I think some people hardly to suggest the Killer card.

I couldn't see that subject in the tech manual that dell provides for download.

Play is better that broken and that's what most people complain about.

I just re-installed one of these.

you have to make sure the upper part of the cover goes into the top of the screen first.

then click the bottom part on. I thought there was something under it keeping it from locking in. but it was just that the upper lip of it didn't get set up right. take it 100 off. and then try agian