Well, I was underwhelmed with the Cruz Tablet which I had gotten because the Samsung Galaxy Tab was listed at twice the price as the Cruz (Cruz debuted at $300 and the Galaxy Tab at $599 with Verizon). Well, after several weeks, I remembered that I had a bunch of credit card points that I had not redeemed for the last two years, and which had a new HVAC system put on it in Spring of 2009. I managed to knock $250 off the price by getting a Best Buy gift card for my points and then bought it on Black Friday when they knocked $50 off the normal list price.
The Cruz Tablet at present is un-rootable due to it having a MIPS processor and a FrankenDroid Eclair Android 2.0. The Samsung Tab was rooted within 5 minutes of me getting my grubby paws on it thanks to Z4Root. I loaded it up with Titanium Backup and ROM Manager (at present no ROMs are available nor can recovery be installed). I have also been able to update the wpa_supplicant file with an aftermarket version (go to the xda-developers forum) which permits ad-hoc WiFi access points - which if you throw in a Droid 1 with the Wireless Tether app you can just use your phone rather than plowing through the 1GB quota in the minimum data plan.
Performance wise, the Galaxy Tab runs circles around the Cruz Tablet. I have downloaded epubs on both devices for "Tom Jones, a Foundling", main point being the document is LARGE and I wanted to push the limits. It takes over one and a half minutes to load the book on the Cruz Tablet - imagine what the load time would be if you had a Harry Potter or Twilight Saga book to load. The Galaxy Tab takes under 30 seconds to load. Extra-large PDFs have a similar result with load time, only there is an extra piece, going page to page in the Cruz increases the larger the document, sometimes taking several seconds to go page to page, while the Galaxy Tab is comparable to my desktop computer for processing page to page. Also the Galaxy Tab will allow you to install the direct from Adobe version of PDF Viewer, whereas you cannot install Adobe's PDF Viewer on Cruz, but must use Quick Office to view.
The Galaxy Tab is also noticeably lighter than the Cruz Tablet and so it fits easier in the hand. The Galaxy Tab also has a front camera, a rear camera with flash, and Bluetooth - none of which are present on the Cruz Tablet. One thing the Cruz Tablet has going for it is that it recharges decently over a USB cable plugged in to a computer, the Galaxy Tab barely keeps the battery topped off during use if plugged into anything other than the USB power brick that it comes with. Please note that the Galaxy Tab also uses a proprietary cable - wheras the Cruz Tablet uses a standard micro USB connector. Also, if you attempt to order a replacement cable for the Galaxy Tab, make sure the vendor has a picture posted and that it looks a heck of a lot like an i*Phone charger cable (unfortunately a slightly different form factor!). I have seen quite a number of eBay auctions which say they are charger kits for the Galaxy Tab but they show a micro USB cable - the same as the Droid 1 phone would use.
Galaxy Tab cable
Mini (L) & Micro (R) USB cable
On other notes, Angry Birds runs on the Galaxy Tab, does not run on the Cruz Tablet. The Galaxy Tab is running Froyo so it has a much better chance of being a longer term device both for support and application compatibility.