I used to use a Senseo (at least 2 years, anyway), but it was getting hard to find the pods to fit my Senseo locally.
At that point I looked at the Tassimo and the Keurig systems. I decided to go with the Keurig machine - mainly because there were so many more varieties of coffee and tea available in K-cups (at least locally).
BTW, I saw an article on Bloomberg (Iphone version) that mentions that Starbucks and Kroger are having disagreements regarding the use of Starbucks coffee in T-discs. Apparently Kroger sells the Starbucks coffee in their stores and fighting a decision by Starbucks to cut back on bulk bean sales and to move into the single-serve market (presently the fastest growing area of coffee sales.

Charlie