This would be the "Holasim" they sell for Spain. It uses the Vodafone network, but the performance is laughable compared to my Vodafone prepaid SIM.

Question,. Some eSIM's are data only
and others data and voice?

Yes.

And some are voice&SMS-only.

It comes down to the kind of plan that is affiliated with the installed eSIM.

So there may be three options depending on the carrier?

No one else seems eager to reply so here's my take on this question.

It seems that the esim provider negotiates what services they will offer from each carrier. Flexiroam now offers esims for data as well as their original sim stickers and also nano sims I believe. The original Sim4Crew had voice service available, but I don't know if that is still true. Their website has changed, and is a little confusing to me. I'm hoping the 3 UK network goes to the esim option soon, as they will probably have the voice, text and data package available, just like their triple cut sim cards. Basically, you'll need to decide what you need for travel and then maybe just ask on this or other websites where to find it at a good price & service.

The Airalo-sold eSIM for US data is problematic in my experience where playing around with cellular data settings doesn’t work to reliably fix PDP authentication problems.

Haven't seen mention of the MTX Connect eSIM, does anyone have experience with it? A pretty straightforward global SIM like a few others, decent coverage and a nice little "Free Chat" option. Just considering it for my son who will be in Costa Rica for a school trip. We have T-Mobile so free 256kb/s data there, this is an extra "just because" I want to try it, and have a second option that doesn't cost a ton. 4Gb/14 days for < USD 30 and simple to setup before hand, worth a try.

so for eSIM iphone if I delete one I can add another one, so technically I can add and delete eSIM unlimited?

No real reason to delete eSIM; you should be able to have at least 5-10 eSIM's installed on your iPhone and just choose one to be active at a time. I guess if you hit whatever the limit is, you can start deleting eSIM's to add a new one.

It's super convenient, I've got like 3 eSIM's that I'm testing and it's easy to switch between them as needed.

Seems like the majority of offerings are data only - which I assume in part is to get around the ID requirements imposed by many countries which appear to apply to phone/SMS but not data only products.

So I've tried the MTX Connect eSIM I mentioned above. Super easy to setup an account online and order a SIM; cost EUR 5 and includes an EUR 7 credit (Chase denied the charge at first but approved after I responded to their fraud detection).

Super easy to get the eSIM working on the iPhone. I then downloaded their app which has a nice interface to manage your eSIMs, topups and data packages. You can use Apple Pay to add to your balance. I have the 7-day Free Chat since it's a new SIM, and that worked well (roaming on AT&T in my area). Their support has been pretty responsive to my inquiries. I feel fairly confident this will work well, as advertised, when my son goes to Costa Rica in April.

Their pricing is very simple and covers their global roaming area, so a nice option for travelers hopping through different destinations too. One can perhaps find a cheaper option for specific local regions, but overall this seems better than similar Flexiroam and Gigsky packages.

I use the three HK e-sim for china, just so I get past great firewall. I have managed to activate it in the UK, but it activates quicker when in HK.

I'm normally a Ubigi man for anywhere else, I find them to be the best, pricing and easy of use, however I'm going to Pakistan and they don't offer a data package for there.

I see a few comments on Flexiroam?

Anyone else have any experience with Airalo? only a few comments on here and they don't seem too positive.

Regarding the data only esims, shouldn’t we be able to place/receive voice calls
with Hangouts, Viber, WhatsApp etc?

Can someone confirm?

Airalo esim details. Great article here on installing and trouble shooting an esim.
The useful part of the article is toward the end.

The QR code activation thing had me confused.

https://upgradedpoints.com/airalo-esim-review

Yes, absolutely! That's what most people do.

Even better is with IMS (IP Media Subsystem, I believe) in the latest build of iOS 13. If your main SIM carrier, say Verizon, has no service it will simulate the data connection on the second sim/eSIM as Wi-Fi and turn on Wi-Fi Calling so you can call and receive texts for free.