These days, we've been mentioned by Marcus Lasance, an independent IAM consultant who formerly managed MaxWare U.K., in his blog. Dave Kearns commented on this today in his Network World newsletter. Both, Marcus' blog and Daves newsletter were about IAM in Europe - and the fact that there are many more vendors and integrators out there than are visible at first glance. And yes, Kuppinger Cole as an analyst company covers them, but isn't limited to them - for sure we are in touch with the US vendors and companies from other countries (for example Brazil, Australia,...) as well.
My personal opinion is that there are two really important aspects in choosing a vendor: He must be able to deliver to the customer. That might be a limitation - as well for US vendors in Europe as vice versa (and for any other regions). And his product must fit the requirements of the customer. That might favor local vendors which support local regulations, local languages, or just are in sync with concepts and methodologies which are used in specific regions. But there are as well European vendors acting successful on a global basis as (more frequently) US vendors being successful in Europe.
Overall, I fully agree with Marcus and Dave that it is important to consider all choices. Big vendors can be the perfect choice - as well as smaller local vendors. But you will only know when you consider all choices. By the way: There are as well European vendors which don't fully convice me - and no one provides a solution that fits to any use case, for sure. To support the decision, we're constantly providing reports for vendors from all over the world. There will be, by the way, several new and updated reports about European vendors within the next three weeks, including companies like Beta Systems, BHOLD, Engiweb, Evidian, G+D, Omada, SAP, and Siemens, to name just a few - complementing the available series of reports which as well covers companies like IPG and Völcker.