Ease of implementation is the 7th factor to consider in your CRM selection. You'll need to rely on a CRM partner for this information, as they are experts in the field. Whether or not you use a partner to implement is ultimately your decision but you should ask one for 2 estimates: time and manpower needed.
It is most likely the data you gain from a CRM expert will be as if they are doing the implementation so you'll want to add additional time for an internal implementation. I ...