I've had a variety of Elinchrom sofboxes in the past and I'd say that most of them are pretty good (I don't include their cheapest single-diffuser ones in that) I agree with Dave that they're good products, and good luck to any manufacturer who produces good products and charges a high enough price to allow the Company to grow and to invest money in future development - but I agree with Paul, I wouldn't say that they're the best.
Personally I feel that Chimera (who AFAIK invented the softbox as we know it today) are the best - excellent design and really good quality materials. Someone asked me once what was so special about them, my answer was that when I shot fashion with them they made cheap clothes look expensive - the light is soft yet crisp, and many of the cheap softboxes just produce soft light with no crispness.
I'd place the Bowens Wafer high on the list too. The concept of a shallow, space-saving design like the Wafer is flawed, because deep softboxes tend to produce much more even illumination, but the Wafer is an excellent design and uses very high quality materials, which helps it to overcome the problems normally associated with shallow softboxes.
But I have to say that I have enormous respect for the opinions of assistants like Dave - assistants have to turn out consistently high quality work in all sorts of studios with all sorts of different equipment and usually have far higher levels of both skill and knowledge than most of the people they work for. When I did it myself I learned an enormous amount about how to 'make do' with often totally inadequate tools, space etc. It was back in those days that I formed my opinion about Chimera