How hard/easy is it to adapt to a 40% keyboard like the JD45 coming from a 60%?

[knowsnokb]

How hard/easy is it to adapt to a 40% keyboard like the JD45 coming from a 60%?
Do a lot of people use 40% keyboard as their main keyboard? Or is just a hobby thing?
Has anyone bought a 40% keyboard but ended up going back to a 60%?
Thank you for any opinion

[Badwrench]

Its not bad.  I use a jd40 pretty regularly.  At first the hardest part was getting used to my right pinky resting on the enter key and tucking it down for period.  I just forced myself to use it all the time and now its no problem.  I also printed out a cheat sheet of the function layers that I kept in front of the board until I memorized the locations (almost all punctuation and all of the numbers are in the funtion layer).  Now I just have the sheet in my drawer in case I need a refresher.  The jd45 with his caps looks like it will be easier to adapt to.