Ha... all you guys saying its useless without trying it!
If your not too fussy with your results on the glass then a rinse bar probably wont make much difference, whenever I try rinsing on the glass and check later some windows just don't come up good. Hydrophobic glass especially gets sideways runs of spotting off the bristle tips.
For me the rinse bar allows me to keep the brush on the glass and acheive a very good finish with no spotting, which is why it makes me a lot faster.
The downstroke is the rinse, you need to deal with the top frame first and once up and once down and done! If ita a wide pane of glass then just fanning it and scrubbing and rinsing at the same time. You can be sure that your not leaving bristle tip spotting with a rinse bar.
The hydrophilic glass is a doddle with whatever you use but the rinse bar is the only thing that solves the hydrophobic glass rinsing problem for me, fan jets don't have enough water weight and pencils take all day.
I would say its only going to be a help if want to eliminate the possibility of spotting whilst being quick. I love it!
(I'm coastal BTW)