I plug my 8900 in every night -- either to a PC or to the wall -- same routine I've used for years with my 8700, 8800, 8100 and 8300. Since loading up OS .152 on the 8900, although I use the device heavily all day, I haven't seen the battery dip below 75% by the time I plug it in after 14 hours use.
For the way I use the 8900, I'd rather keep it sleek and slim. Even hesitating, for pure aesthetics and size, to put an Innocase II on my javelin! (although I probably will to protect it).