I probably need to upgrade this laptop since it doesn't connect at 5G to the modem wifi.
If you're having speed issues with your 2.4Ghz connection there are often settings adjustments that will improve the speed of devices that utilize that connection.
I have no 5Ghz connectible devices (save for the Raspberry Pi 3 B+ I got a few weeks ago), and all of my 2.4Ghz connected devices have internet speeds that are within 98% of my Ethernet cable connected devices, meaning that with a device connected via the 5Ghz band I'd see virtually no improvement over my 2.4Ghz connected devices.
I only mention this as I'd hate to see you spend hundreds on a new laptop with a 5Ghz connection only to find that your WiFi speed isn't any better.
However, if the speed of your 2.4Ghz WiFi connected laptop is noticeably lower than an Ethernet cable connected device, and no settings adjustments help to bring that 2.4Ghz speed up, a 5Ghz connection may very well give better results.
AMD FX-6100 | Samsung 250GB 840 EVO SSD | Western Digital Blue 500GB HDD | 16GB DDR3-1866 | EVGA Geforce GTX 550ti | Windows 10 Pro 64-bit