I'm currently trying the enhanced formula bar and so far the new functionality is an improvement.
One idea I'd like to see implemented is that the formula bar automatically resizes when clicked into and then collapse to normal size when clicked out of. e.g. if the formula is 10 lines long it would expand t show all 10 lines when clicked on but then reduce bar to one line when clicked out of.
This would remove the need to manually expand or use the down arrow or even scroll on formulas that aren't too long.