Despite the improved accuracy, the app shouldn't chew up too much of your valuable device space. Each language takes about 30MB to 40MB , Google said. And you don't need a powerful device, either -- this should work with "low-end" phones.
The smarter offline feature is only available for about one percent of all Translate users as of today, but it should reach 99 percent of them by the 13th and everyone by the 15th. So long as you don't need it right away, you should have everything you need to find the washrooms on your next vacation.