That's interesting. The cheapo Tesco one I have at the moment certainly lights less well than the previous one I had (which was also cheap but I can't remember the source, and probably less cheap). Perhaps I'll get a Weber replacement for this summer...
I think it has a lot to do with the way they've designed the funnel in the base. The Weber has a conical grid in the base, so the coals in the middle are set higher than around the edge within the funnel. I think that this helps a lot with the airflow and thus allows the coals to catch alight much quicker. The cheaper one I have doesn't have such a deep conical grid.