also have complete set of both Mame2010 and Mame2016. I don't want to keep both romset on my HDD and waste a lot of storage space for nothing. Could anyone suggest which romset should I keep for future use?
Keeping on-point, when possible, 2016 should trump 2010. For one thing, you could 7zip 2016 ROMsets and they'll work nicely. If you have any questions about compatibility, refer to my Arcade Recommendations List. You'll note that lr-fbneo is highly recommended, but you'll also note 2016 vs. 2010 compatibility for other ROMsets.
Hope this information is useful. It is also highly optimized, in case you just don't want multiple variations of some of your games. Or don't care about the 300+ Mahjong games, or gambling/casino games.