Let's not get nuts, now! Is the arranger section the "whole show"?? Just because the patterns sound good - does that mean that anyone that plays it will sound good?
I think you're stretching the poit a liiiiitle out of perspective. The 740 is a good intermediate keyboard, with some very good sounds that are "borrowed" from the higher end machines. It will never be in the same league because it is missing too many features that PLAYERS(remember them???)want.
In order for a board to be truly professional it needs to address many needs of many different players. Lots of control - lots of variation - lots of ways to customize...... etc.....etc.
If all you want is patterns - sure the 740 has nice stuff. So does Casio, and Bontempi and lots of other low end machines. The real difference is the player features that you miss. As a lightweight alternative to a professional keyboard, the 740 comes in at a good pricepoint, but still misses the boat in controller areas. The new PSR2000 has added the option to shut the sustain off the left hand so, at least a bass part can be played on it now. Maybe I can utilize that for my nursing home shows......who knows.