I have used the 1150-style readers since 98-99 when they were still distributed by RCA/Gemstar with the old OS. Since then I have tried borrowed various devices, Palms, more recently the Nokia 770, and after all that time I still prefer the 1150.
It is sad that with all the technological advances, not one single manufacturer has come up with a more USEABLE solution, even e-ink, which promises better readability, doesn't provide something as basic as back-lighting to read in low light.
The 1150 used to have some software annoyances, but most have been ironed out, and with the latest firmware upgrade it is a mature, stable platform that even offers things like (free) Oxford dictionary lookup within any books etc.
It is admittedly like a brick, but that means also it is almost indestructable, washable, and offers up to 20 hours (!) of continous use with the backlight on thanks to the large battery. I can read in my bed (the only time left these days), fall asleep, it will turn itself off, and doesn't care if it's dropped off the bed or I turn around onto it. And thanks to its many brightness levels, I can adjust it for the most pleasant low-light reading experience. (BTW, that's the only factor affecting battery-life, contrast doesn't influence it)
The only downside is that for the best reading experience, you may have to spend some time prepping the files (html) The good thing is that thus you can have it exactly your way.
Some basic links:
http://www.ebookwise.com/ebookwise/ebookwise1150.htm
where you can get it with a 64mb card, which I STRONGLY recommend, since even the free dictionary would use up more than half of the built-in memory.
Also, obviously, you can buy pre-formatted books, the library being essentially a spin-off from Fictionwise.com.
http://www.ebooktechnologies.com/support_download.htm
The official, free software to create books from HTML files. Most importantly, it includes a free viewer which allows you to preview/read the books exactly like they would appear on the device.
It is important to note that .lit files are essentially HTML files in a compressed wrapper, kinda like a zip file, with or without DRM. So, using ConvertLIT, you can turn them back into HTML, which you can then use with the above publisher.
There is an apparently fairly decent amateur/enthusiast Publisher/Librarian software available that may make things easier. It is also available on the ebookwise site, and there is a free 7-day trial. I cannot comment on it since I haven't had any need for it.
I have included a small Quick reference I created a long time ago that shows all the fonts and characters available. You can view it with the Viewer included with the free Publisher above. Please note that it is NOT a zip file, but this forum does not allow .imp files, so you will have to edit the filename, and REMOVE the .zip at the end.