I use a lot of quarter round bits in my work and I have found that I get at least 50% more use from a 1/2″ shank bit than from a 1/4″ shank before needing to resharpen. I ask the owner of MVP Sharpeners here in Houston about that and he said “I’ve been trying to tell people that for years!”
I use Amana bits and the two shank sizes cost the same.
Other tips –
Some collets vibrate more than others. I got 3 before gettin one that ran smooth.
Have a sturdy platform (router table) and go with constant even pressure and speed. After a while you can tell what feed speed is best for the type wood and bit.
Keep the bits clean. I take the bearing off and soak the bit in acetone or lacquer thinner.
Occasionally put some light oil on the bearing. Run the bit on some scrap wood to get rid of the excess oil.
I’ve never had any luck trying to ‘touch up’ a bit using a diamond hone. I usually get worse results afterwards.
Find out what grit your sharpening shop uses. MVP uses 600 grit and I get a much better edge than from the original sharpening by the factory.
For what that might be worth!
PlaneWood by Mike_in_Katy (maker of fine sawdust!)