Originally Posted by
garykung
I used 2 different devices (ZTE and Alcatel) with T-Mobile Hotspot. Both are T-Mobile certified (i.e. branded). A side-to-side speed test comparison with my cellphone (not T-Mobile certified) revealed my cellphone data speed, on mobile tethering, was significantly faster than Hotspot. Specifically, I used a iPhone without active service and connected my cellphone and Hotspot respectively. And I used Ookla App to run speed test on the iPhone. The App reported my cellphone data speed as 14Mbps and the Hotspot as 2-3 Mbps at max.
I'm not sure which of them you had exactly, but when I was looking into devices I could hook into my existing home network to serve as backup internet, I noticed that in the case of Netgear's at least, they were stuck at LTE category 4--even the newest models. This means that they only supported one LTE band at a time (e.g. no aggregation), which depending on where you're located could mean that it latches onto a band that's assigned less spectrum and/or is more crowded. That could explain a significant part of the slowness issue along with the well-known hotspot throttling that T-Mobile does.
Unfortunately, as mentioned above, hotspots aren't exactly high priority for the manufacturers, so they tend to get features long after regular phones. Phones also aren't exactly designed to be hotspots 24/7, so I can see heat, etc. killing them a lot sooner.
(That all said, the 5G hotspots will likely do significantly better regardless, assuming you even have 5G in your area.)