Support varies, depending on the political suituation at Digi (which is ever changing). When things are going well, I get answers within hours for basic things; when things are heating up (lots of layoffs), it can take days. It is a corporation with all the inherent problems.
Cameron tries to help out here, but he and 1 or 2 of his co-workers are the only ones who actually understand what is going on with the Connect parts, everyone else just quotes the knowledge base.
The level of forum support also changed dramatically when the ConnectME v2 came out about a year and a half ago. A lot of queries are not answered any more, even with a "I don't know". You see that there is a lot of zero reply threads here.
This may be because the queries have moved away from the NetOS programming questions which are what forum peer members like me can help with. I used to be able to help with almost every question, but I cannot help with all the new pre-built stuff (I use the API and write my own server). I still try to answer whatever I can, but my responses have gone from 10 a week to 2-3 a month.
As for calling Digi and talking to them, unless you get Cameron or one of the others who understand the part, you are out of luck, and because they actually know what they are doing, they are constantly out of the office putting out fires and so are almost impossible to get a hold of. I hope that Digi pays them enough - if they ever left, the Connect series of parts would die within 6 months.
The ConnectME is a wonderfully powerful part (with the exception of a poor serial interface to the hardware) that can solve a lot of problems, but I would give support a 4 out of 10. They try, but the corporation doesn't give them much by the way of internal resources to work with. If you are looking for a solution for your app, it will probably do the trick, but don't count on a ton of outside help.
-Erik