A corporate investor brings credibility, distribution and sometimes a large cheque. It can also bring information rights a competitor would love to have, a signalling problem if it declines to follow on, and a buyer who has seen your numbers before anyone else.
None of this means saying no by default. It means negotiating the side letter as carefully as the price: limited information rights, no board seat, no right of first refusal on an acquisition, and a clear understanding of who inside the corporate sees the data.
If those terms are not available, the logo is probably more expensive than it looks.