As an owner of several megachangers I would recomend them. I sold my 5 disc NAD t571 for a Sony 300 disc unit and have no regrets after a year and a half. 5 discs still meant all the cases and dics to handle. The 400 disc Sony DVP-CX985V plays SACD and was given a great recomendation in The Perfect Vision this month.
One issue is that DVD changers are slower to load discs compared to CD changers due to process of disc identification and loading. The advantage is that you can view your entire collection on screen. As Turbodog recomended, a spreadsheed makes the process of finding a disc very simple and fast.
