There used to be a list of what the ipad1 adapter combo supports. Not sure where that is but basically, consider any video and still photo ( slide show included) with or without sound can display on your hdmi tv. The major difference is that with ipad2 you can display the entire ipad2 screen and then if you wish to just see the video, simply expand the ipad2 window to full screen. In ipad1 you never get to see the ipad1 screen on the TV, just the slide show or video full screen. In my Home theater, I have the adapter connected to a hdmi cable to reach from my couch to my AVR's front panel hdmi jack. For home theater, ipad 1 works fine. For presentation and training, I'd think the need to see the ipad2 screen on display is more important.
PQ looks good and is great for stuff like Youtube video which is the only way I can easily watch youtube on my 110" screen. ( I could access with PS3 but that is complicated; ipad is much easier ) The quality is fine but varies as does all stuff with YouTube. Netflix, on the other hand is very consistent and equals my Netflix on the Xbox360 or OPPO. Netflix on the PS3 has more capability in audio and PQ.
The adapter also has a way to plug in a power supply but so far I have not had a need as the battery life on the ipad is more than enough for an evening of ipad/HT viewing. I did test it, however, and that too works the same as ipad2 use.
Hope that helps.