Large firms have done a lot of business with a lot of companies. When we needed some urgent advice, our big firm couldn't give advice specific to the situation before a conflict waiver, which delayed things significantly.

We don't use them anymore, and I don't think there is much value added to justify the added cost of a large firm.

Do go with vanilla docs though.

The top firms are expensive, but worth it. It's usually not worth trying to economize on lawyers unless you really know what you're doing. Once a startup is established, it can make sense to try cut down one's legal bills by e.g. hiring an in-house counsel, but when you're inexperienced you don't want to be cutting corners in the legal dept. Better to overpay your lawyers than end up with some disastrous term in your funding agreement.