ESPP at large pharma/biotech companies

Curious to hear from others in the industry. Some big tech offers an ESPP with a discount on stock purchases through payroll deductions. I wanted to get a gut check from people who’ve actually used one.

A few questions for anyone willing to share:

• which company provides ESPP in pharma/biotech space?
• what discount % and look-back terms does your plan have?
• Do you sell immediately (lock in the discount) or hold longer for the tax treatment?
• Any regrets , like ending up too concentrated in your own employer’s stock?
• How do you think about ESPP vs just maxing out 401(k)/other accounts first?

just real experiences from folks who’ve been through a few offering periods. Thanks!