I'm in a similar boat as bigsnake49; my dual monitor desktop is where I get hard work done, unless I'm away from it, in which case my MacBook works just fine (especially now with 8GB of RAM!). But for lighter tasks, my iPad gets used heavily. The proptortion of time spent between my workstation, my notebook and my tablet varies depending on the day, but unless I'm on the road the notebook goes pretty much unused, primarily due to the iPad.
I was very close to getting the Transformer Prime, but the third-gen iPad is actually superior to the Prime tech-wise, and I could get the iPad with built-in VZW LTE. The LTE, paired with a built in GPS, proved to be incredibly useful over the past few weeks when travelling and apartment-searching. I could have done similar things with my Epic, plus a tethering app and a Prime or other WiFi-only tablet, but for my purposes the additional $130 I spent to get the cellular-enabled model has been money well spent.
One thing I wouldn't consider at this point is using the iPad as my only computer. Nor does it negate the need to bring a laptop on trips longer than a day or two. There's just too much it still can't do at this point...and an Android tablet would be in a similar boat, at least for now. Same reason I have at multiple points carried two laptops around when going on trips. Laptop #1 was my MacBook most of the time. Laptop #2 was either a Windows machine (for light-ish gaming; my MacBook's HDD isn't big enough to dual boot) or a Chromebook (for excellent battery life while doing web stuff).