Do it quickly the question pool has been scheduled to change around June 2016 to include most of the existing questions and adding more digital oriented questions will probably result is a slightly larger pool of questions...more to prepare for.
The General Class question pool is good from July 1, 2015 until June 30, 2019. The pool contains 462 questions. The test is 35 questions. You need to answer 26 correctly.
The current Extra Class pool expires on June 30, 2016. The new test pool goes into effect on July 1, 2016 and is good until June 30, 2020. In either case, the test is 50 questions. You need to answer 37 correctly. The current test pool (2012-2016) has 700 questions. The new test pool (2016-2020) has 712 questions.
Questions removed from the 2012-2016 pool: 131
New questions added to the 2016-2020 pool: 143
Questions which have been updated: 60
So yes, the new test pool is slightly larger, but only by 12 questions which is only about 1.7% larger than the old pool.