I don't think it's geared up for home theater as it doesn't have such a good scaler/deinterlacer built in IIRC, but if you use an HTPC that's not important.
It's something like 852 x 480 in resoltion so I would think it sits underneath the 830a due to the scaler spec. I don't know what kind of colour wheel it has, and that may make a difference in colour reproduction and/or rainbows. It's an entry level DLP DC2 machine.
I've not had a play with the Optoma H27 as yet and I have to say with the ThemeScene H30A now selling at £995.00 it doesn't seem a huge leap up from £850 to get the H30A; which is excellent.
Whilst both projectors come from the same 'stable' the ThemeScene units have had a fair amount of 'tweaking' for optimum Home Theatre performance whereas the Optoma units are very much 'Multi Purpose'.