Not sure about anyone else but I am finding the group feature to be very restrictive by being limited to contacts.
Fairly often you may import lists of companies in market sectors and not have a contact for yet or perhaps your initial contact is with a customer service adviser when making first contact to large corporations, especially when cold calling.
Not being able to make specific groups for companies is very restrictive as an example I would like to group all Local Authorities in a Group to work through, but without a contact I am unable to do so, only by inputing a Generic "contact" to make it a member of a group. Also named contacts move and leave companies frequently making group memberships far more labourious to keep upto date.
This is where I find the software restrictive when you deal with "companies" (b to b) rather than individuals,
A simple fix allow "Companies" to have Groups too. I would imagine it would be an easy update - hotfix