The sensitivity area of the LDR is, in fact, a lot better than the photo transistor.
But, as you have noticed, is extremely slow.
Photodiodes can respond in picoseconds if used properly, and some have areas larger than a typical LDR. The larger the photodiode area, the slower to respond. This one, with 1 cm x 1 cm area, has a rise time of 7 us.