We use assurant for several years now across multiple countries & companies within this organization we get it centrally managed which helps us out as well! - nothing really that I would recommend avoiding when using them but maybe some features do need improvement (like getting an overview over all users).
There are many other providers around though so you should find one near your location who fits best into what kind if environment/projects etc., they're usually more expensive than assurance or at least have different feature sets / offerings however there's no real downside either from my experience thus far unless price was key factor.