^Same with me. I got the same modem I posted above, around 20 days ago, and I rebooted it only twice in those 20 days. It remains on 24x7.
But its my first TP-Link product, so cant say about the long run.
But it remains a lot cooler than my previous Modem(Netgear DGN 2200v4) despite being on 24x7.