It depends on what kind of reading and what kind of subject matter but in general yes.
Novels tend to take me a little longer to start up. This usually has to do with initial setting and placement, needing to hear the voices actually resonate in my mind as well as really get into a reading mood. Thus I tend to start out a little slower and pick up the pace quickly enough.
This tends to be novels only though as I read a lot of academic works much more quickly at a relatively even pace provided there's not a host of new terms and definitions. Reading though a history book for college courses wasn't difficult or lengthy in the least, logic on the other hand had some nightmarish sections of flipping back and forth.
Plus, if it's a draggy book it takes longer to read unless I just point skim. But if it's Jane Austin forget it. I can't retain any of it, can't get into it, can't so much as glimpse the pages for more than five minutes without finding something that desperately needs my attention such as just about any single thing other than reading another line of the novel.
Threads on forums, ''well, there's many pretty pictures... who are you... oh yes! Akay I remembers. Now what is it you're saying in a pleasant voice reminiscent of Stephen Fry hmmm? Ahh, excellent! Now if it isn't you and you, ho-ho what tricksters you are! So what have you to say.'' Thus you see a drastic speed drop there too.