He renewed the technique of organ building, exhibiting an outstanding fine art when designing and building his famous instruments. There is a before and an after Mr. Cavaillé Coll. His organs are "symphonic organs", that is, they can reproduce sounds of other instruments, and combine them as well with extraordinary and monumental sound, in both volume and pitch range. The biggest expression is the Grand Orgue of the Saint Sulpice, Paris. Featuring 101 stops and five manuals (keyboards), this magnificent instrument, totally built upon mechanical action, it is a candidate to be a "mankind monument" endorsed by United Nations.
Mr.Cavaillé Coll was also well known for his financial problems. The art of his handcrafted instruments, unparalleled at that time, was not enough to ensure the firm´s perdurance. His firm was acquired in 1899 after his death by Mr. Charles Mutin. He continued in the organ business, but by the years before World War II, the firm had almost disappeared.
Marcel Dupré stated once that "composing for an orchestra is quite different than composing for an organ... with exception of Mr. Cavaillé Coll symphonic organs, in that case one has to observe an extreme attention when writing for such kind of majestic instruments."
Fortunately, many of his organs still remain until nowadays.