Pros
Great coworkers, mature practices, will gain a lot of knowledge depending on your department. Opportunity to be domestically mobile within the company if you want live in subpar cities throughout the US. Great opportunity if you enjoy being paid in experience instead of money.
Cons
Very common for loyal long term employees to be pigeon-holed. Numerous long term employees retain basic analyst titles. Negotiate your salary before joining the company, not after. Only way to get higher pay or title is by being very mobile in your career either within the facility or among other UTC locations. Loyalty and hard work will not get you a promotion. High favoritism for merit increases and promotions, management doesn't reward hard work. There are bi annual employee reviews where management pulls up each employees profile. A negative perception any one manager in the meeting will end that employees future prospects, I've seen it many times. Make sure to manage how others perceive you. If you're not on management's gold star list don't plan on going very far. They'll be happy to keep you in a role as a work horse and lie to your face to keep you happy. It's all about who you know and how others perceive you rather than what you've accomplished. Very high attrition rates. Expect to work long hours with little gratitude depending on your team.