Pros
Definitely a great place to get a solid foundation in networking and beyond (but not too much further than that). It is also a great career first-job since it really beefs up your resume assuming you actually take advantage of your time and learn; you must not screw around and instead use your time wisely. Except for one or two people, all of my former coworkers are genuinely great people to work with both on a professional and personal level.
Cons
The first thing you will notice (actually, you probably won't notice it at first since you would otherwise not take the job) is the extreme low pay. I had a bachelor's degree in information systems and was pulling in 42k when I left; within a year after quitting I was at close to double that rate at a much more enjoyable company as a network engineer. I simply did not realize my market value. The "bonuses" if applicable are a joke; I got $100 and a 2k raise after truly working beyond what was expected of me (again, your work is not appreciated). That is when I decided I needed to quit and started only doing the minimal amount because I realized my work quality was not appreciated. After ~70% of the NOC quit within the span of ~4 months (this occurred about a year ago as of writing this), I hear Transbeam panicked and bumped up the pay of the current employees still left, however from what I understand it still is nowhere near market value. The NOC still remains a skeleton crew, which means extra work for you. Transbeam is somewhat of a family owned business, and unless you are senior management, your value is not appreciated at all; you are simply an expense in order to keep the angry customers from actually canceling. The best way to understand what the company is like is this: Before I quit without notice, the company previously notified me that they found I "owed them" vacation days that I took, neglecting to address the fact that each one of my vacation days were approved; apparently I owed them 40 hours. They threatened to not pay me upon departure from the company. When I quit, not only did they not pay me, but they also did not pay me the OT hours I put in for that last pay period as well. Needless to say, I am in the process of working with the NYS Dept of Labor to rectify this. I personally know of other people who have had similar experiences to this upon quitting. Unless you are fresh out of college (or worse, no college) with no skill sets and dead set on doing networking, stay away from this company. If you do end up joining: get serious, be responsible, learn, get contacts at other ISPs, then quit in a year.