These days I prefer "。ｊｐ" to ".com"
I am Japanese who does type in. (Rhys, there is at least one Japanese man here who is indeed typing in!)
at the moment, i type mostly ascii domains in because there aren't many Japanese IDNs around. however, there is one Japanese IDN I do frequently type in. that's Olney's キーワードアドバイスツール.jp. (KeywordAdviseTool.jp) Olney has both .jp and .com and I actually used to use his .com domain name more often. However, after some time, it started annoying me that I had to convert from Japanese typing mode to ascii one each time i type キーワードアドバイスツール.com. Converting the typing mode takes me only a second but it is certainly better if I don't have to. And the thing is, I don't need to covert typing mode at all if I use .jp domains. that's because i can keep using Japanese roma-ji typing mode and type in "。ｊｐ" instead of ".jp". And it works perfectly fine. you cannot do this with .com because as soon as you type .co in the roma-ji input mode, co gets converted to hiragana こ.
now i am so comfortable with typing "。ｊｐ" that i almost never uses his .com version of keyword advise tool.
it's the same thing when i randomly type in some top Japanese IDNs just for the sake of fun. These days I almost always start with 。ｊｐ to see if there is any website up. dot com sounds good and looks kinda better than .jp, too. but .com cannot beat .jp when it comes to the ease of typing in.
this is just one man's experience. and i have no intension to conclude that the same would apply to other japanese people. and i know that there are many people here who believe that .com is sperior to .jp. and you thinking that way is perfectly fine for me. people have different opinions and that's cool. i am just talking about my experience and i have nothing to defend.