I used one like that and it was excellent if you've had a c-section as it avoids you having to bend over too much. It saves water too as you only need a small amount in it rather than having to run enough to put a few inches in your main bath.
Ds's did grow out of it rather quickly though and we moved on to a reclining bath seat in the main bath
We did get a baby bath but only used it a few times before getting a reclining bath seat from M&P that had suckers and stuck to the main bath. Then we progressed to a bath ring. The baby bath was just too cumbersome for me. Otherwise, when we first got DD home we used the bathroom sink which was a good height too.
I'm with Gemy - the reclining bath seats are great, particularly if you have a bad back, are recovering from c/s or have funny sized/shaped baths. Plus you have your hands free to wash/play with baby. Ds loved his and we used it until he was about 9 months old.