They've been around for a long time. They make custom frames under the XACD brand and also do OEM work for several mid-range Ti brands that sell frames in the ~3k USD range. Historically, theyve been a quite a bit more expensive than Waltly (and harder to deal with), so they are less popular.
These days the prices should be closer, but the pricing model is really different. They will give you a lot of options to choose from, and you pay for each one vs. having preset price points. Overall, it's a lot less consumer-friendly.