It's totally reasonable to say "I only want $ from big firms" because they can actually do followon rounds. As much as USV seems to be regarded pretty well, the

It's totally reasonable to say "I only want $ from big firms" because they can actually do followon rounds. As much as USV seems to be regarded pretty well, their stated preference is to only put a few million in over the life of a company - if you're expecting to build something capital intensive, you're better off going with a firm that can back you sufficiently. Even relatively early rounds ($12M at 60 pre for Uber, etc) are getting done for more than the smaller VC firms want to put in over the entire life cycle.