If customer service matters, DUI hands down. This is from dealing with both.
18 months ago I was selling Santi. I have to say they build a quality product. I have now changed to DUI as my drysuit of choice for my shop. Both manufacturers build a quality product (I was not a total fan of my DIU TLS-350, but LOVE my FLX), customer service, and turn around time were 2 major reasons. The fact that they are an American company is a plus for me. I had some customer service issues with Santi and a suit that came with a factory defect. Luckily I was able to repair it for my customer but it was not handled well.
Your mileage my vary.
18 months ago I was selling Santi. I have to say they build a quality product. I have now changed to DUI as my drysuit of choice for my shop. Both manufacturers build a quality product (I was not a total fan of my DIU TLS-350, but LOVE my FLX), customer service, and turn around time were 2 major reasons. The fact that they are an American company is a plus for me. I had some customer service issues with Santi and a suit that came with a factory defect. Luckily I was able to repair it for my customer but it was not handled well.
Your mileage my vary.