I've worked with IB (though it was only my University Project, done on a 60-day trial version in April, May, connected to Web through PHP3 scripts - BTW why the hell ibase_*** functions in PHP3 documentation are only mentioned by name - FIY, at least they're similar to other ie. ODBC,MySQL or PGSQL functions).
Ibase is very user-friendly, I think more than PGSQL, it has some PL/SQL language, though it doesn't support such constructs:
SELECT name
FROM (SELECT name FROM companies);
...Ok, I know it may not be a completely correct statement, but it was written on the fly....
One GREAT thing is possibility to define collation sequences - PG needs to be compiled to use locale - I'm Polish and we have those strange letters that need to be sorted.
That's all, an IB-port would be nice(I've seen one on the Web, but it was for the 4.x linux version - too old)
