For us the bumbo seat was the best buy out of everything we bought in terms of value for money.
When Isaac first started using it, he didn't like to be in it for too long but as he's got older he's enjoyed it more. He's seven months now and still uses it. It's handy in the mornings when I'm having a wash, I can put him in it and know that he's safe by my side.
It was invaluable for weaning, I put him in it on the counter top whilst I fed him. Made life very easy.
They are comfy as they are squidgy, it holds them in such a good position as well. A nice change from them always being against something i.e. car seats, bouncing chairs etc.