Well, practically speaking, if you have a Surface Book, it has the TLC (slower) drive, the Samsung PM951. Microsoft isn't interested in exchanging SSDs.
Theoretically, if there was a possibility, take a look at these benchmarks from Anandtech. Here's the 512GB MLC Toshiba:
And here's the 512GB TLC Samsung:
Sequential is what you're looking for, as 4K is for very small files (important for loading Windows and all applications). They're both fast, but the MLC Toshiba is nearly 2x faster in writing. However, these are 512GB drives. As you get to smaller drives, the difference between them gets even bigger.
The bottleneck will only happen if you are reading/writing from an relatively speedy external drive (no USB thumb drives, but external SSDs) OR copying within a drive. Moving files within a drive isn't affected by the drive's speeds. And it only really matters if you do it often.
Say you have 100 of these 20.4MB RAW files; that's 2.04GB. To copy those files (for a backup), the 512GB Toshiba would take ~2 seconds, while the 512GB Samsung would take ~4 seconds. Once you go smaller, you'll see an even bigger difference. Copying those same files on a 256GB Toshiba would take ~4 seconds, but a 256GB Samsung would take ~7 seconds.
Not a lot, but if you do it often (and with more files), the differences compound. The 128GB versions are pitifully slow on the Samsung; it would take you ~14 seconds to copy 2.04GB. I've not seen any benches on the 128GB Toshiba, but it should be close to ~5 seconds (if we guesstimate a bit).