You'll need to email the uni to check for a definitive answer, the issue will be a combination of welfare and admin as being away from the uni for 2 years straight is less than ideal and they likely don't have a weighting setup for people who do both.
A master's with year in industry is 5 years not 4 years btw, as your year in industry will be between either 2nd and 3rd year or 3rd and 4th year, usually the latter for an MEng. That said I believe Southampton offers semester in industry courses rather than year in industry, and this is included within the 4 years, though obviously you miss out on some content in order for that to happen and semester long industry placements aren't as easy to find as year long ones.
I'd say the pros and cons are pretty much the same for both, except the year in industry is more likely to get you a job at the end, and study abroad is going to end up being a bit of a holiday probably. Pros being you get to see a different kind of working/education system which will help you develop your work ethic when you return and thus get you higher marks, cons being you will forget/miss out on some stuff so need to catch up again throughout the year.