Pros
After being with the company for 5 years, I've been promoted multiple times and have a team of people working under me (I've been in charge of a team after only 18 months at the company). I've gained great experience as to how to be an effective business professional, and I am constantly given feedback (and praise when it's earned) on a weekly basis. I have been traveling on business for the company on almost a monthly basis to visit cities all over the US. Management is open with employees about future plans for the company and the development of our software, and it is very easy to approach senior level management and even the executives (VPs, CEO, etc) to have meaningful conversations about your work. As long as an individual has a strong work ethic and the drive to get promoted, it is easy to excel at Cvent (as there are many opportunities for advancement, especially since the company is growing so fast - it had 300 employees in 2007, and has 900 currently, with plans to grow to 1,000 employees by the end of 2012 - so plenty of room to move up in the ranks) and increase their bonuses/compensation package. Work days are about 9 AM to 6 PM or so, so the hours are not even remotely grueling. From a social standpoint, the atmosphere is friendly and there are many company-sponsored Happy Hours and holiday parties at great locations (the 2011 Christmas party was at the National Museum of the American Indian (a Smithsonian Museum in DC) and the 2010 Christmas party was at the House of Sweden in DC, just as two examples).
Cons
It can sometimes be easy to potentially slack off with regards to your work schedule or daily performance, as there is no clocking in when you get to work or clocking out when you leave. You need to manage your schedule so that you do work the appropriate hours. People without self-discipline may find it easy to fall short of the expected work hours, and would thus find themselves at a disadvantage compared to those people who put in the effort.