I doubt it. Why? Because I have one of the "slower" LTE phones. I haven't noticed it, especially when dealing with the crap DSL my parents have in their new house because AT&T is the devil. 1 Mbps. In 2016.
I digress. It's fast as freaking hell doing everything I have tried. As with a lot of number things, it's probably so minor based on what people actually do that you'll never notice. Same with the imperfections of compressed audio through Apple Music or the iPhone 7 Plus camera compared to a DSLR. For most people's general purposes, you will not care. I could deafen the neighborhood with songs from Apple Music in my car (an amp and subwoofer help a wee bit) and so far the iPhone 7 Plus camera looks as good as anything for the average shots I'm taking.
Also, I think the story on those flash speeds got a little blown out of proportion. I didn't find actual stats, but the more accurate framing may be "128GB, 256GB iPhone faster than 32GB iPhone" instead of the "32GB iPhone is slower!" clickbait that you likely saw. Extra parts (I forget their names) are added to speed up writing since there's so much more space on which to write. Plus they cost an extra $100 and $200, so the fact that they get some sort of speed boost shouldn't be a complete shock.