We have 4 children one of the reasons we are looking into home exchange. We have a large beautiful home well set up for a family, swimming pool; play area, loads of space. Do families actually have success swapping and finding good size properties to accommodate them? I am unsure if it’s worth being a member at this point
Hello. Yes a lot of families are exchanging without any problem. You can join for free and only suscribe to finalize a first exchange 
so worth trying
Yes. We joined in the past and did many exchanges with our three children, where we all had our own room. We also had two swaps where the boyfriend of our daughter came with us.
It is certainly possible, and it sounds that you have a more appealing home than we did and we succeeded in finding reciprocal swaps, too.
Many members are looking for a place with a swimming pool I think, so you’ll probably be swapping soon after you join. 
Family of six here and open to hosting other large families :-). We are hoping to host here as well so if anything ever brings you down to the area please do keep us in mind! It’s a great spot for a few families to vacation together and a fun local area to explore in Fall City! We are new to home exchange but also came with the hope that we can find family homes to vacation at more easily and share our own!