Let me start by saying that Tushy's customer service is excellent. I had some installation problems and they responded quickly to all my concerns, even to the point of reimbursing me the cost of a new toilet seat! I would have given them three stars but they got the extra one for their service.
So, the bidet: If you have a perfect butt, it may very well work perfectly. If you're older and have internal hemorrhoids (full disclosure--that's me), the clean-up will take more than a wipe with just a cloth after you're done. It does cut down on toilet paper, but it doesn't eliminate the need for it. It's great for touch-up squirts through the day though. Oh, and check the rim and toilet seat for splashes after you're done.
I chose the Spa 3.0 because of the warm water, but be forewarned that the first squirt will always be cold! It tempers quickly and you can warm it up with the temperature knob. Another warning: don't start it up with the temperature set too high. OUCH!
FINAL VERDICT: I'm glad I bought it. There's a learning curve but it's worth the money. I don't know if any other bidet would work better for me.