I think you have to look at who you’re selling to. So if you’re selling into the SME space and you are selling to the owner of the business; inserting an SDR into the process may be elongating the sales cycle.
It’s hard enough to get to that person, but then on top of that, set up a meeting and then say, “Oh! Can we set a meeting?” And you have to wait. As opposed to the full-cycle sales representatives, you get to the person and you can launch the sales process right there. It depends on what you’re trying to accomplish and how busy your AEs are.