John:
I love sod-wall bunkers when they are beautifully constructed, which seems to be very rare nowadays -- so many of the famous links are just making them as steep and as high as possible, instead of letting a shaved bank work its magic from the top down. Muirfield is one of the few courses that still does them right -- it's about the shape more than the wall.
Bandon Dunes' bunkers are not sod wall bunkers, of course, but medium- and small-sized grass faced bunkers. To me they look more like Gleneagles' bunkers than Muirfield's, but they're fine. They still have their own sand-erosion issues (I've seen liners exposed on them), but there is not as much sand surface to erode.
Blowouts are fine, too, although I'd agree they are becoming overused. Not in Bandon, though. We'll likely have some more of them at Old Macdonald, because once you get them started, they ARE natural there. As at Ballyneal, we're making them as shallow as we can to start, so it will be a couple of years before the sand erosion requires much action. Which does make me wonder about the restoration work we did at Pasatiempo -- the opening-day pictures of their bunkers looked quite shallow in many places, but perhaps MacKenzie was planning on Nature making them deeper.