Maybe Lout has improved a lot since I last tried it -- which, admittedly, was a long long time ago -- but my recollection is that the quality of its typesetting

Maybe Lout has improved a lot since I last tried it -- which, admittedly, was a long long time ago -- but my recollection is that the quality of its typesetting was always very greatly inferior to that of TeX's. It might have 95% of the functionality as measured by feature-counting (though ... there are a lot of LaTeX packages out there, doing all kinds of wacky things) but that's not worth much if the output just doesn't look good.