If you're staying in a country a day or two, no it doesn't make sense to get a local SIM. Though with EU abolishing roaming surcharges when you cross borders between EU countries, it may make sense to get a SIM in the first country if you plan to visit several EU countries over a week or more.

It takes a little research to find out what the local SIM options are. There's are threads on FT and frequently updated info on the web. Then you find stores near where you'll be staying. I just consider it a part of planning and researching the trip.

I've never had problems with local SIMs not being as advertised. It can be a hassle in some stores, where you have to wait for a clerk who will sell you the SIM, activate it for you.

Now if you only need occasional email, web and Google Maps, while you're away from hotel wifi, then the free T-Mobile international data is enough. But I often find, regardless of the size of the hotel, that hotel wifi is unreliable. It's either off or congested or whatever. So if the mobile data isn't too expensive, I'd rather have that at least as a backup.

Of course some people can say, why do you want to even try to have the same kind of Internet speed and reliability as you would at home. Relax, you're on your vacation!

Well if that's how one approaches it, they probably wouldn't be in this thread or other threads about getting connected overseas.