Maybe it's just a Placebo effect, but I find that I get a better 4G+ reception when disposing my ARCHER MR-600 vertically. The router uses the beta firmware that allows the manual selection of 4G LTE bands. Also, it's easier for me to read the LED's status from my desk.

Am I the only one to doing this with the router?

My ARCHER MR-600 in vertical position, next to its predecessor (TL-MR3220).

It gives sufficient stability, but can be reinforced at the back if required. My router is powered by a mini UPS (4 to 5 hours of battery life) for a 24/7 service (except when MR600 loses Internet connection!).

Previously used for vertical mounting of an external hard disk drive.

In vertical position, I'm getting often 2 bars in reception (75%) or, at worst, just one bar (50%). Before, in horizontal position, I usually got a single bar (25% to 50%) which gave a "good" but lower speed.

I've already had better results in upload speed (it depends of day's time).