Hi Hollo, I used a baby hammock for my first
DS who was a bad day napper (only slept if I held him), it was WONDERFUL! I could actually get stuff done and he loved being in it. He would sleep in his cot overnight really well though. I didn't actually move him from his hammock until he was nearly two! When I did move him, he went straight into a toddler bed and we had no issues whatsoever. My sister moved her
DS over from a hammock to his cot at 6 months of age with no problems either.
The other side of the coin - I tried my second
DS in the hammock and he wouldn't sleep in it! It actually disturbed his sleep rather than helped it, much to my disappointment. Luckily he loves his cot so we don't really have any issues there.
Do you know anyone who owns one that you could borrow first to see if your bub likes it? Alternatively you can hire them so it may be worth trying one out that way. If you are worried about costs, you can buy them second hand on eBay for heaps cheaper.
Good luck with your decision!