I used Viz (Max's little architectural brother) for 2 yrs, and was just about to purchase V-ray because I tired of the plain (flat) old Viz renders. I started using Mental Ray and got good results on exteriors, but was worried about going to interiors when I found Kerkythea. ... after 2 years in VIZ I was considered better than most at my work in VIZ (but it's like giving a haircut to someone one-hair-at-a-time-painful-to-use), I was very ready to find something simple- can't I just get a good render engine for SketchUP w/out the hassle?!
I would say that Kerkythea is not your average 'cheap or free' program. It integrates more easily with SketchUp than Max, and you light it up inside of SketchUp... add materials in SU, etc... but then you have choice of ray tracer (which is VIZ scanline render - but KT renders faster than VIZ in that mode) or you have automatic wonderful preset Radiosity settings (PM+FG in KT-speak), plus you have unbiased methods (MLT+BiPT very similar to Maxwell) and for exteriors I use Progressive Path Tracing (similar to Vray, as I understand) No other program, free or pay can offer you that.
My gallery is here and it has side-by-side comparison with Viz, Viz+M-ray, and Kerkythea.
I'd say if you want something more advanced than Podium, and just about as easy to use, but with as many or few advanced options as anyone could want, then Kerkythea is the way to go. SketchUp is free, Kerkythea is free. AutoCAD-$4000, VIZ-$4000, V-ray $1000. hmmm... I did the math, the work, and compared. I decided.






