Well I have had the opportunity to try both the new model (push button plunger) and the old style squeeze bottle. After lots of tweaking and screwing around I will be ripping the new improved model off my bike. My dad has long since thrown his "old style" in the garbage.
In my humble opinion, don't waste your money on either, stick with a can of old fashioned chain lube!
The new style does not like any kind of grit or gravel as it will keep the plunger depressed and bleed all the oil out making one hell of a mess. :headbang:
Take it for what it's worth....