I am one of the lucky guys who got a HP Touchpad 32GB for $149.
Can't help smiling :-))
p-reader native is good, sideloaded books on the kindle app works with "Kindle Import" only up to a certain page-limit and i still did not figure it out, how to get it tweaked to get them all complete.
There is also "readMe" and "Book Reader", but they are all not satisfying.
epub's i usually read with my sony psr 505, my nc rooted or my nook touch (even sometimes modified on my palm live drive).
when reading them on the touchpad i use "pReader native"
for reading pdf i bought "Quickoffice" and "Picsel smart office". first one is also good for reading MS-Office Stuff, later one can not only read them, but you can work with them like the "Office to go" on the palm life drive.
They are both better than the pdf-reader, that came with the Touchpad!
in the end, the Touchpad is a great thing to take on vacation, with the build in mic and headphones even VOIP is possible - but i will always include an e-ink device for smooth reading.
Battery life on the HP Touchpad is great. on my last trip from Berlin to New York (9 1/2 hours) I watched one whole season of "sons of anarchy" and half of "Ghost rider", before it run out of juice
keep reading and support Kovid with Callibre
all the best