Trying to dig without a toothbar you have a 6' wide cutting edge to force into the soil and it doesn't do very well. The "teeth" on the toothbar penetrate easier than the solid cutting edge. In addition to improving your ability to dig, the teeth are great for grubbing out roots and getting a bite underneath the rootball of small trees and popping them out. The toothbar wasn't an expensive item, and can be easily removed if you want, but mine stays on all the time. The only time I've found it to be a disadvantage is trying to backdrag and smooth an area out with the FEL bucket.
Top-N-Tilt refers to hydraulic cylinders on your 3pt hitch... "top" is a cylinder that replaces your top link and you can make adjustments on the fly with the cylinder instead of stopping and screwing the top link in our out. "Tilt" is a cylinder that replaces your tilt linkage adjustment, normally on the right side when looking at the tractor from the rear. This can also be adjusted on the fly instead of stopping, getting off the tractor, and making manual adjustment to level up or get the correct angle with your implement. These options get their most use probably from box blading, which requires changes to the adjustments periodically, but are handy in many situations. In addition to that, they make it mighty easy to hook up to attachments. I had my dual remotes set up with a joy-stick control mounted where the fender meets the fuel tank to the right behind the operators area, and I can reach it from the ground behind the tractor to make minor adjustments to help in attaching implements, etc.
Dual remotes... is two sets of remote hydraulic outlets. My primary use right now is one for the top link cylinder and one for the tilt cylinder. There are many attachments that can use the remotes... some disks require hydraulics to lower/raise the travel wheels; some box blades have hydraulic activated scarifiers, etc.
As far as the quick attach on the new loaders, I believe that skid steer type is available now, which hasn't been with the 1400 series. As I said previously, I'm using the pin type quick attach and it satisfies me. Another thing in its favor is the price. I don't believe quick attach is standard on the loaders, but it might be.