Both should be reliable and last for many years. I don’t think theres a big difference between wings from different manufactures - there’re just air bladders with a hose attached.
I've been using the signature 30 lb for a bit over a year - it’s still looking good and can handle any abuse. Very streamlined and has a strong cover that you can unzip - so you can repair the bladder if it should some how get punctured.
If I went for one again, and god forbid for some reason went back to diving wet, I would be tempted to get a Signature 40 lb - the 30 lb is the right amount of lift for when diving, but a bit more lift on the surface would be handy when in heavy seas if you're not wearing a drysuit that you can inflate, and the 40 is not that much larger than the 30 in profile.
So, to conclude, go for which ever one chicks dig the most…
Cheers,
Rohan.