I have had a mixed experience with them, bought a C456 frame off them, shipping was very quick but there was an issue with the BB threads, emailed their warranty and was treated like a child, told I had cross threaded it and they were not going to do anything for me.
Gave up, took it to my LBS who chased the threads (for free I should add) and it has been fine ever since.
Emailed them twice since then regarding a tech query on an El Guapo frame which they didn’t know the answer to and a potential crack on the aforementioned C456 but they said it was nothing to worry about.
So they have always answered my emails just not always helpfully!