I had a bit of both with 2 kids. 1st one, I spent ages in the birthing pool but in the end had to get out, epidural and forecp delivery as everything just stopped.
I am blaming the fact that I was so comfortable in the water, I got in at the first twinge and basically stopped moving about.
With DC2, I was determined to keep moving / upright for as long as I could bear it - pacing the room, hanging off DH, bouncing on the ball etc.
Then I got into the pool and was able to deliver DD - it was amazing, classic picture really, on my knees and she swam up between my legs and into my arms - incredible moment.
I wore a tankini I think for the first one but then just pants and a sports bra the 2nd time.
1st time, they kept making me get out for monitoring which was horrible but 2nd time they managed to monitor me in the pool the whole time which was ace.
I would 100% choose the pool but depends on the set up in your local hospital wether you get one.
For us, we found out on our tour of the ward that shift change was at 7am and 7pm so I was very lucky and decided to go in around then rather than stick it out at home for another hour which meant they diverted new staff from the normal labour ward straight into the birthing centre wing with me so I know you often won't get to control at what time you need to go in but it worked for us!!