Yes, that's my understanding:
"Most Li-ions are charged to 4.20V/cell and every reduction of 0.10V/cell is said to double cycle life. For example, a lithium-ion cell charged to 4.20V/cell typically delivers 300–500 cycles. If charged to only 4.10V/cell, the life can be prolonged to 600–1,000 cycles; 4.00V/cell should deliver 1,200–2,000 and 3.90V/cell 2,400–4,000 cycles. Table 4 summarizes these results."
http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries
This is also a factor in storage (or standby), they degrade faster at higher charge levels just sitting there.
You should not take anything I have to say as any more than my honest experience and advice, I make no claim to be an authority but rather back up as much of what I say as I can. That's what you should depend on, the sources I cite. Like the above 'Battery University' page on the subject. I see nowhere in it information to back up the idea that constant charging to full voltage is a good thing. In fact, the opposite.
Or that depth of discharge (to say 3.0 Volts?) is a significant factor.
The math seems simple enough to me. Normally you get 300 to 500 cycles (depending mostly on temperature). Reduce the charge by 10% and you double that number., and 80% improvement in total useful capacity. Do that again, give up 20% per cycle by going to 4.0 instead and you again double the number of now 80% cycles. Four times as many times .80 is 320%, over 200% improvement, more than triple the number of sessions over the battery life time. Some will see that as a good thing.
This idea is also backed up by the Military specifying exactly this. For gear they want very long battery life in (don't want to deal with battery failure) they specify a charge under 4.0 Volts to force the makers to use more battery capacity (charged to lower voltages) to give that lifespan, despite the cost and weight increases:
"Lithium-ion is charged at approximately 4.2 ± 0.05 V/cell except for "military long life" that uses 3.92 V to extend battery life. Most protection circuits cut off if voltage greater than 4.3 V or temperature greater than 90 °C is reached. Below 2.50 V/cell the battery protection circuit may render the battery unchargeable with regular charging equipment. Most battery circuits stop at 2.7–3.0 V/cell."
http://en.wikipedia.org/wiki/Lithium-ion_battery
Thanks to Al Gore inventing the Internet, each guy can do the reading and make up his own mind.
OF