I really love the IT CC cream and can comment on using the Tarte BB Primer and trying the Ponds you mentioned. I haven't use any Tarte foundations though.
For me the IT CC cream is superior for a few reasons. I love the all physical spf 50 and the fresh faced finish it provides. It's not too dewy but its not matte either - more like a satin finish to me. My skin leans dry and this does not accentuate any dryness. It covers beautifully and I don't need a huge amount.
The Tarte BB Primer is similar to the IT CC cream as far as coverage but it is way more drying on my skin than the IT one. It also leaves my skin looking a bit "flat" due to the drying effect. If you like a more matte appearance you may wish to keep using the Tarte BB Primer.
The Ponds BB cream has a nice appearance on the skin - maybe even a bit dewier than the IT CC cream but provides no where near the coverage IMO.
Hope that helps you decide. I did really like the Tarte BB Primer but the dryness is what prompted me to try the IT CC cream. And for me, I absolutely love the all physical spf 50 the IT CC cream offers. HTH