Pros: free coffee. nice kitchen.
Cons: open bay seating
They talk well, and it seems like you are about to be with the best company you ever imagined. But they have no commitment to their employees. Toss this one out and get another.
Coming to work at ManTech is a sink-or-swim effort. If they like you (for whatever reason), then you are golden. But if you aren't on someone's "favorite" list, you are just another piece of the scenery; as long as you are making them money, you have a job.
There is in-house on-line training. Some of it will help you toward certifications (like ITIL). However, the in-house training will not improve your standing in the company.