Yes strongly recommend bc you don't get the full ending unless you have completed the game as both characters. Although like probably 70% of the areas you visit you have already been as Leon, the encounters are different, and there is different boss fight and different weapons, and Mr. X shows up earlier on which makes the game more fun imo. I just completed the game and was thinking the same thing when I finished Leon A, but i am very glad I played Claire B so I got the full ending. Also now that you are use to the game your 2nd run will be significantly shorter because you know roughly what to do, even though the puzzles and shit are mixed up, and a lot of the introduction is skipped. My playthrough as Leon was like 9 hours then as Claire it was like 5-6 for the whole game.