I just did mine for the first time last night and like it so far--probably better after I get to shampoo it tonight! I have really thick, really long hair (past my waist) though. I think having thin hair would probably make it easier to get the henna in, at least! I cheated and used Light Mountain "Color the Gray" henna. It's the real henna plus the other two kinds (netural henna and dark(?) henna) mixed, in my case, to produce a light brown shade. My hair is about a dirty dishwater blond or light brown and this works pretty well.
Light Mountain has other, lighter shades too that might work well for you. They have both a normal series and a Color the Gray series if you either have light hair or more than 10% gray hair (I do, way before my time
). Some MDC women don't like the series, but it is 100% natural. Plus, you can still add some of the henna tricks too, like chamomile grounds, etc.
The only thing I didn't like about Light Mountain was that the Color the Gray was in two steps, which meant mixing the henna and applying and rinsing twice. So, I think this summer I'll probably start playing around with henna alone and adding various components. The "Henna for Hair" site has a lot of suggestions too.
Not sure about the texture issue though. GL!