Does Postgres have an equivalent Connect By feature? Last I checked it didn't. If you don't need to scale your hierarchical data much, its pretty handy. I'd prefer to go to Postgres too.
PostgreSQL 8.4+ has recursive common table expressions. I don't know if they do everything that CONNECT BY does, but I know that they do everything that I've ever used CONNECT BY for.
The better way is to use WITH RECURSIVE CTE's. See http://ledgersmbdev.blogspot.com/2012/07/ctes-and-ledgersmb.... for how we use them in LedgerSMB for hierarchical data.