I just upgraded my Macbook Pro with a larger SSD drive. I stuck with Crucial, upgrading from a M4 256 GB to a M4 512 GB. After a cloning the drive with SuperDuper, I installed the new, larger drive in my MBP. I immediately noticed it took significantly longer to boot up, specifically, it spent a longer time on the white screen, before the gray apple is shown. I tried a few things for troubleshooting, including setting the startup disk in preferences, but still no joy. Finally, I tried a trick from the old days, zapping the PRAM. I say old days, because I haven’t zapped PRAM on any of my macs for years. Anyway, that worked perfectly and it’s back to booting quickly again.
Zapping your PRAM is done by pressing your command, option, P and R keys all at once right after power on. Keep them pressed until you hear a second start up chime.