The advantage of the COB LED strip light is that the light is continuous so you won't get any hot spots reflected in the countertop. But the SMD LED strip light is cheaper and the hot spots can be mitigated by using a channel with a frosted cover.

@wdccruise Thanks for your reply! So if I use COB LED strip light, do I still need to use the aluminum channel and diffuser? It seems that COB strip light would be more expensive. If I use a SMD LED strip light with aluminum channel and diffuser, would that be able to achieve the same result as a COB LED strip light? Also does CRI (Color Rendering Index) play any role between COB and SMD LED strip lights? Thanks!

I'd watch these:

• I bought every LED Diffuser channel on Amazon to find the best one (ignore the dancing girls at the beginning).
• The BEST Low Profile Diffuser Channels for COB LED's
• Spotless NEON Effect LED Strips, which is Best?
• 7 Common LED Strip FAILS and How To Avoid Them

Under a kitchen cabinet I'd always use a channel and diffuser to provide a finished appearance.