That's the right direction, in my opinion, but the article is a bit superficial. The main thing which isn't covered is the easiness of the activation of a foreign SIM. Also, of course, the easiness of obtaining one.
I didn't personally encounter any other place in Europe where they would require an official ID just to sell you a SIM. But activating a SIM can still be a hassle. In Germany, for example, it took me a few weeks to convince the operator (Fonic) that I'm OK to use their services without a proper German address. Before that, the card was blocked.
In France you also seem to enter a valid address if you're activating a SIM via the Internet. Not sure if they block the cards with suspicious addresses though. Mine (Lyca) is OK for more than a month.
In Ireland and the UK they don't need any address, let alone ID. SIM cards are activated immediately and it's up to you if you want to register online afterwards.
Ukrainian and Thai cards don't need any registration either but that's probably not very relevant here.
Other important thing is regular and easy topups. Otherwise, you risk losing your number if you're stuck away from that country for a while.
I never tried topping up Irish numbers with non-Irish credit cards but I some how suspect it's more than likely. I never heard about any restriction on using the foreign credits cards in Ireland. In the UK, however, you can't apparently use a non-UK CC for online topups. From the operators I know, at least two, O2 UK and Three UK, don't allow it.
In Germany, it appears it's actually quite rare to topup by CC as Fonic dosn't allow it and I think O2 DE started allowing it only recently. With a German CC only.
In France, Lyca allowed me to use an Irish CC online without any issues. Also, Lyca's expiry is probably the best in the country: mine shows 8 years from now after only one topup. I did notice that most other prepaid offers are ridiculously short lived in France.
And yes, the rates. I tend to believe that using a foreign SIM can be cheaper than the local one in Switzerland. I think TIM ( http://www.tim.it/estero/dall-estero...paese=SVIZZERA ) now upped their rates to the common EU denominator 29 cent but still it fares well in the Swiss cohort: 45pr Lebara, Lyca; 35rp Yallo; 33rp Orange; 30rp Sunrise, Coop; 29rp Mucho; 28rp M-Budget.
Irish rates are comparable to the Italian.
O2 IE ( http://www.o2online.ie/o2/roaming/co...nd&net=default ) and Vodafone IE ( http://www.vodafone.ie/planscosts/pa...y/roaming/map/ ) put Switzerland in the same EU bracket (though it is officially not part of the respective telecoms agreements, as opposed to other non-EU states in Europe, e.g., Norway and Iceland) while Three IE ( http://apps.three.ie/roaming/prepay/ch ) and Meteor IE ( http://www.meteor.ie/do_more/roaming...europe_zone_2/ ) utilise the Swiss marginalisation with the appropriate rates.
UK operators seem to generally also charge Swiss roaming according to the EU pricing and with a 24p per minute it's not too bad either.
MVNOs usually price roaming here higher so no surprise Fonic DE has EUR 1.29. But Lyca FR and Lyca IE aren't too bold, in fact. Swiss 35c isn't overly steeper than the EU 29c norm.