This is my experience:
I've bought both, Bilt and Sedici, I have no complains, Sedici has a more appealing design and features most of the times and lifetime warranty. I worn out the soles before the boot got any signs of damage.
Sedici gloves feel more comfortable as they have a softer inner lining. Bilt gloves feel thinner and the leather is no at soft initially until they are broke in.
A set of Sedici perforated leather gloves that is use a lot got the stitches in the thumb loose and it got replaced, no questions asked..
I don't have a Sedici jacket, but have had a few Bilt. On the leather it is a thick leather but it is not as soft as on other brands. I have had issues with the zipper of one jacket that the tabs broke, bilt has 5 year warranty and they replaced the jacket for this. I have a mesh black jacket that I have used for a couple of years under the FL sun, it is comfortable but the color didn't held and nos is a purplish/brownish shade of black/gray.
Mesh jacket compare well against some scorpion jackets I have, however scorpion leather seems to be a finer grain and softer.
Bilt helmets are mad by the Chinese company Yohe (http://www.yhhelmet.com/
last time I checked their helmets were certified with DOT, ECE and NBR) the finish and the materials aren't the best but aren't bad either. With a sport helmet I have, I found that the secure straps are on the short side and stiff and it makes it hard to tie them. The first one I had I returned it when the visor plate holder came off, had a half helmet that was involves in an accident and it did well protecting.
Their warranty is exceptional, they stand behind their product 100%.