Unless you plan on purchasing terabytes of hard disk space for your collection, dont believe their claims that this program will work for you. And yes, I have tried this on multiple Mac's and configurations. It simply isn't what it claims to be. This MDRP claims it all, but when it comes down to it it fails. I emailed support and was told he was on vacation (apparently one guy does this ) and never heard back. Multiple DVD's don't play well, and the newer DVD's simply refuse to burn to a backup.
Just to offer an alternate viewpoint, as someone who actually used MDRP to rip ~1000 anime DVDs, it only choked on 3 discs in my collection, two of which were bum discs that won't play through on any hardware player I've ever tried them on, and one of which is the first US anime DVD ever produced, so there's something weird about the mastering. Even marginal discs that other rippers (RipIt, specifically) had trouble with--it failed on too many errors--ripped properly, and played just fine.
I obviously haven't watched all of the files I've ripped, but every one I have has worked fine, and I specifically tried several discs that I knew were problematic or borderline (ones that were scratched, indie DVD-Rs, RipIt failed on, or that some set-top players skipped with) to make sure that it was doing okay. All have played fine thus far.
Maybe the situation has changed with the more extreme copy protection methods used on modern Hollywood discs, and MDRP hasn't kept up, explaining your different experiences. I did recently time-shift a big-studio rental DVD new release, and it ripped and played fine, so my extremely small sample size didn't show any issues, at least.
MDRP is a one-man operation, with the plusses and minuses that that has. I got a quick response the one time I asked a support question, but obviously your experience was different. It's not terribly expensive, at least, so there's that going for it.
And yes, of course you need a lot of hard drive space. I, personally, specifically wanted "exact" rips of full-sized .iso disc images. It took 3 2-TB hard drives for my entire collection, which cost well under $300, even including the "toaster-style" USB dock for them. I'd rather run a 4-5 disk RAID-5 array with 3-TB disks to allow for headroom and a hardware failure (may still switch to this some day when finances allow), but going extreme cheap and using the discs themselves as the backup does work.
The ability to produce .iso files instead of compacted rips was actually the reason I chose MDRP over other options. I can see why that would make it less desirable to others, and most people using it to produce recompressed video files are running the .isos through Handbrake after the fact, so it isn't necessarily the best one-stop shop, but it certainly does what I want it to, at least as of version 2.5.