I think sposies definitely have their place and would have originally been designed for times like going on holidays.
The only times we've been away are to visit the in-laws and I've used pockets then and washed as required. I think that if we were going elsewhere I'd go sposies so I could have a relaxing holiday - well as relaxing as a holiday with a toddler can be!
It's really up to you, as others have said. Whatever is going to enable you to have the kind of holiday that you want.
