Personally I love travelling light (<10kg carry-on pack for 2 months last year to South America) but it isn't for everyone.
> Laundromats exist everywhere.
Only if you value your time at nearly $0. They are incredibly annoying when travelling - too often a 10 or 15 minute walk each way to one. Great for backpacking, but a complete waste of time if you only have a limited amount of time for your holiday.
