I have used Mares Plana Avanti Quattro fins for about 3 years. I like the fins, but the buckles and straps are terrible. On my first dive (beach dive), one of the buckles unclipped near shore. Due to the current and visibility, it was quickly lost. Luckily, the dive shop that I bought them from helped me get a replacement from Mares. After this very long process, I decided to purchase the locking clips from the dive shop at a cost of almost $30.00! On my next dive (boat dive), I broke a strap while using NO force whatsoever. Luckily I had a replacement with me. When I returned home, I noticed that the strap was obviously defective on BOTH of my fins. The small ridges that the clips use to grip on to were slit down to almost nothing along the edges of the ridges. Definitely a defect in manufacturing. I have been trying to get reimbursed for over a year now, but all correspondence to Mares has been ignored. I can't wait to see them at the local dive show next year!!! P.S. I have close-up pictures (and the actual straps). If anyone is interested in seeing them, email me. I'd LOVE to hear from someone else with this problem.