I just got myself the Sony PRS-T1 e-reader.
While it does support PDF files, processing them is somewhat slow, but I am being told that this is the nature of the display being used (e-ink), rather than the device.
As long as the PDF files are formatted to A5 size they will display well enough. Luckily the DCS manuals are A5 size formatted, but A4 or Letter sized documents will be too small to read and you will need to either zoom or read in landscape mode and scroll.
This works a little slow, because the device has to recalculate all the time.
Even in A5 the letters are quite small though and up-sizing them destroys the formatting on the pages.
Another solution is to turn them 90 degrees and view them in landscape mode, but this will force you to scroll over the pages, but it works well enough.
Its certainly do-able, but I think a tablet might be more comfortable reading the PDF files.
I do find reading documents on e-ink displays less tiring on the eyes, though.