I've bought numerous feeders over the last 20 years to feed my several hundred-strong year-round flock (go thru 1200-1500 lbs of sugar a year in 9 feeders).  Perky Pet's previous (old - 209) version was the best of the rest, but its major downfall was the inability to easily clean it.  This newer version (209B) changes the game since the base easily disassembles and all parts can be easily and quickly cleaned (HUGELY important if you want lots of hummers).  Also, the glass bowl has a much larger mouth, so easier to fill and clean.  Finally, it has a built-in ant moat.