Different nations have different local calendars, which would present an occasional glitch if you are using the missal edition from another country. This would be most obvious in the Propers of Saints, as some of the saints’ feast days are celebrated on different days, depending on where you are located.
The Midwest Theologic Forum edition of the DRM 3rd edition is specific for dioceses of the United States. The UK most certainly has their own edition, and either your parish priest or your diocesan office of liturgy would be a good source for steering you in the right direction so that you spend your hard-earned money on an “investment level” book that is most accurate for your location.
This isn’t unique, by the way, to the most recent Mass revision. My Tridentine missal has sections for the dioceses of specific nations, and even specific dioceses within the United States.
All that being said, however, if you can afford it and want to treat yourself, your own personal copy of the current missal is really nice to own and use! I hope you enjoy whichever edition you purchase as much as I’m enjoying mine.