Are RDX removable disks a good replacement for LTO tape?

I looked long and hard at RDX drives and specified the embedded RDX units in a couple of Fujitsu servers I bought. Here's what I found:

1. Microsoft native backup does not play nicely with RDX, because of the status of removable drives in MS disk management. As a result if you run Windows native backup (e.g. 2008 r2) you cannot send incremental backups to an RDX, only one-off full backups. If you want any nuanced handling of the backup you will need to write scripts.
2. Ditto Microsoft Data Protection Manager does not recognise RDX, which is a shame because DPM is great even for small MS shops who might benefit from RDXs.
3. Some people suggest a product called Firestreamer which lets you use RDX with DPM, but it's expensive and I found it to be a real pain to use and configure.
4. I wanted a portable solution for both offsite recovery and archiving. RDX is okay for offsite recovery but for archiving the cost doesn't work. By archiving I mean taking point in time snapshots of the state of data (say every week or month) so that if I corruption is found then you can go back to the previous state.
5. I bought about 4 300GB RDX drives at list price, but then around 12 120 GB drives on Ebay. This gave me enough drives to rotate media offsite, play with full system restore etc. for a small installation
6. I have to say, that I never enjoyed restoring from RDX - times are about 20-30 MBps for the USB 2 version. You can get a SATA version which will make a slight improvement, or now a USB 3 version which do a lot better. If you are restoring images, the USB 2 version takes a long time. What I did like though was the fact that you could store a backup VHD on the RDX and boot that from the OS. I did this to restore a Hyper V virtual file server when its host disk became corrupted.
7. I was waiting for Tandberg to release the RDX Quickstation autoloader, which there were rumours of at the beginning of 2010. Eventually I got fed up with waiting and bought Fujitsu LTO3 tape autoloader. This gives me loads of capacity, fast restore, no messing about with software issues, and cheap media. Also, backup software understands tape media rotation in a way that I never experienced using RDX.
8. Tandberg have now released the RDX Quickstation and it looks pretty good - I like the fact that it uses the iSCSI protocol with an LTO3 tape emulator, because this means that it will work with virtualised backup software (which generally needs an iSCSI target to backup to tape, because most virtual systems do not give the virtual machine access to a host SCSI port or whatever you need to connect to a tape drive.) Although I like the look of it, and RDX drives are pretty good to handle, and it has speeds of around 70 MBPS, I'm still stuck on the fact that RDX drives are expensive. If you are just rotating 8 RDX drives then you're probably cool, but if you want to archive then you're not.