Generally yes, IP KVMs will work with anything resembling a PC (VGA/DVI/HDMI out, PS/2 or USB keyboard/mouse peripherals). Unless things have changed recently, they're not pleasant to use. Generally requiring Java or ActiveX and having poor mouse coordination (click about 100 pixels away at a heading of 160 degrees from the area you actually want to click).
For logging in and seeing what they see, and doing some basic remote service, yes it would probably do the trick.
Since iLO/iDRAC came into play, it seems like companies really stopped trying to make decent IP KVMs. I'm sure they're out there but they're getting more and more niche I think.