I often translate my way through a good(?) book on the way to work, on train journeys etc. This usually means I'm crammed into one seat, with very little room to move. Previously I used my "Papyrus" denshi-jisho, which being the size of a medium size book itself left me with even less room. I'd be constantly switching between resting the novel on my lap to look up a word, to resting the Papyrus on my lap to continue reading. Being only on my second Japanese book, you can imagine how I have to look up about 10 words on some pages, meaning a lot of switching, and a fair amount of irritation.
The Tattoo, on the other hand is spectacularly dinky, so I can rest the Tattoo with Aedict on one page while I read the opposite page! Very handy.
I also criticized the sorting of results.. But after using Aedict for a few months, it turns out that this is not really much of an obstacle to looking up words.
Aedict's new layout is very nice too, showing you the most recently viewed results, which is pretty useful. Aedict has also been able to deinflect verbs for a while now, which has on occasion saved me a fair amount of confusion.
More than anything Aedict's lookup speed is its greatest strength. When emailing my wife and need to use a technical word (lately a lot of words about pregnancy!) its actually quicker for me to whip out my phone and search using Aedict, than it is to open a new tab, load up wwwjdic and look up a word online! Its that which impresses me the most about Aedict.
I still find looking up kanji a bit of a hassle, and that is the thing that takes the most time (I can still only translate maybe 2 pages of my book per bus ride, the same as with my Papyrus). I attribute this mainly to the kanjipad (and I guess, my slow pace at learning the stroke orders)
As well as Aedict, I've sampled a few Japanese IMEs. I have to say, none of them are perfect. Simeji tended to mistake where I was pressing (possibly due to the Tattoo's smaller screen resolution, but they should support it since it is in the market, so your guess is as good as mine), and OpenWnn Plus (which I recommended last time) had a tendency to crash. I now use OpenWnn/Flick support, which is basically the same as OpenWnn, but it doesn't crash on my Tattoo! However, when typing English, I still prefer the HTC's default input method, since you can generally just bash the keypad in the general region of the letter you're aiming for and carry on. No way can I type even half as quickly in English using any of the Japanese input methods.
I've seen some Japanese/Chinese handwriting development occuring, which I'm very excited about. Perhaps that will be useful in looking up kanji in the future? I hope it works with the HTC Tattoo!
Overall, the HTC Tattoo is a great device for Japanese, I'm spectacularly pleased with it.