I don't own either.
But in a similar case I was deciding between an iPhone and (Samsung) Droid Charge. (Upgrading from original Motorola Droid 1)
After loving all my Samsung products (tvs and monitors) I took the plunge with the Samsung Droid Charge.
I quickly came to regret this decision. Samsung has this phone stuck on Android 2.2.1 and I notice a lot of software bugs. Two of which drive me crazy: twitter and my voicemail programs with fail and only load again after a phone restart. Also my GPS locking, that was fantastic on Motorola Droid original, is finicky at best on this Samsung product.
(This maybe not a problem for the Samsung Tab, but I also can't get rid of a ton of Verizon bloatware without rooting the phone and voiding my warranty).
All my work and personal computer are MACs, which I love, and I paid the price by trying to diversify.
Not sure if this is the input is valid for iPad versus Samsung Tab but, if not, at least I was able to rant