Q. Does the Microsoft Assessment and Planning (MAP) toolkit have a limit of 150 machines to collect from per MAP instance?

A. No, the MAP toolkit doesn't have a hard limit to the number of boxes that can be monitored from a single MAP instance. Microsoft publishes 150 as a number they tested, but I've personally seen environments where a single MAP instance monitors over 500 boxes. The number will vary for each environment based on network latency, bandwidth, and performance of the MAP machine. You should monitor the performance of your MAP instance to ascertain how many machines can be monitored successfully and the effect it has on the network. MAP tries to gather statistics on each machine every five minutes, so 150 machines means 30 per minute and 500 means 100 per minute.