Pros
Nice, supportive environment (depending on the sub-team you join). Decent starting wage. Good for career starters, since it's a safe environment to establish yourself professionally. Maybe it's also good for very senior professionals that expect to start with a high salary and not get any raises. Normally, you end up with good managers that don't micromanage (there can be exceptions). They are very typical about 8h workday, and they pay overtimes. Team dinners can be a fun experience, you may get to eat somewhere fancy.
Cons
Obsolete technology that is not used anywhere else. You are not really progressing in your career path. You won't get any raises if it's not January. In January, the company will voluntarily give you 2-4% raise regardless of your performance (however, they claim that it is based on performance). The intention behind the voluntary raise is that they don't negotiate with you. Generally, they will try to find ways to squeeze work out of you without compensating you fairly (e.g. increasing your responsibility/work load/work output without giving fitting raises). Flexible schedule merely means that you can choose to start working at a specific time (8, 8.30, 9, 9.30, 10, 10.30 or 11), but you will have to stick with it. If you join a team that has early or late meetings that you are required to attend, you have no choice but to choose one of the schedules that suit your team.