True, I wouldn't get a Mifi unless it had all the LTE bands for Europe. Same with any cheap Android phones you might get.

I had a 3G Mifi which I used to use and it worked but the battery life wasn't great. I paid about $110 at the time.

I also wonder about cheap Android phones, whether it will have all the LTE bands or good battery life.

I just use iPads, because for $129 more than a Wifi iPad, you get one of the best LTE base bands. I've used them all over, Europe, Asia, Oceania, US, and never had problems with it not supporting any 4G network.

iPads have big batteries to power those big screens, so it's a very useful combo when using with local SIMs while traveling.

A valid concern. My Moto E4 has only LTE 7 for use in Europe. When I used it in Portugal in May, I did get LTE sometimes but was often on 3G - which, actually, wasn't so bad, really. I have an older Moto E2 - the "international" (Indian) version that is a bit slow now but has all of the European LTE bands (just not any of the US ones!), so I think I'll hang on to it for future use if only as a potential hotspot.