The number one con during my time at rewardStyle was that deadlines were incredibly unrealistic and resulted in substandard products or products that couldn't be released at all. Ultimately that meant a higher stress work environment, faster burn out and an overall feeling of frustration. I'm not sure if that's a flaw in senior engineering management or simply a power imbalance where product and business completely overpower the technical expertise needed to accurately assess deliverable time frame but it's there.
Aside from that the salary was a little below market rates, and I talked to a number of employees about it so that was a consensus opinion. Additionally people would go more than a year without any pay raise. This affected morale and was a silly thing to allow as even if the employees were not performing in an excellent way they're either contributing well enough to earn something more based on company growth (which it was) or cost of living or they're stuck in status quo land and need a kick in the pants.
And lastly, tech debt tech debt tech debt. There was soooooo much tech debt that was created by having to do things the dirty way and soooooo much that was obviously created before me from, I can only imagine, similar situations, that touching anything was a gamble with disaster.