Thoughts on Time Capsule.

I'm getting close to filling the 256GB storage on my Macbook Pro Retina. It's time to buy some external storage and was hoping to go to something at least 1TB and has quick transfer speeds. Obviously Thunderbolt drives would be my first choice. I fixed on getting the Buffalo Thunderbolt Mini station that is $250 for the 1TB but then something else caught my attention, The 2TB Time Capsule. I like the idea of automatic backups and according to Anand it is a solid wifi station which could be a step up from my Airport Express. My concerns are primarily the reviews. Nobody really speaks poorly of the performance but almost everyone runs a red marker all over the device's reliability stating that it dies out in less than 2 years with no options for repair. My other concern is that data transfer over wifi is too slow and that a model with a thunderbolt cable will come eventually. I'm just looking for personal experiences with the machine and if an Airport Extreme with an external drive plugged in will act the same with auto backups?