Pros
Decent place to start out of college. Because of large AUM, immediately get access to top sell-side analysts, most investment conferences and above average management access - this all leads to opportunity to develop solid contacts in investment industry for when you choose to leave PGI. Great place to work if you are from Iowa, you actually like Iowa and want to spend your whole life in Iowa. Mid Cap Blend manager is excellent. Great track record.
Cons
Iowa is a very dull place. Constantly reshuffling teams (separate Value & Growth teams across all mkt caps, then sorted by Large, Mid, Small across all investment styles, then turned into a quant shop where analysts are basically window dressing.) With some exceptions, ineffective at attracting money outside captive Principal pension client. Probably because of combination of middling investment performance and poor marketing skills (both from marketing staff and investment staff). Mediocre PMs and analysts (again, with some exceptions, of course). Most people who have real talent leave for better pastures. Lot of Iowa based people who, if they keep their head down, don't take many chances and don't blow themselves up, can have a long, decently compensated career.