I tried iPhone 4 with iOS6 and iOS7 to test and websites load roughly the same amount of time. A few seconds later, no issue, if it took mins extra, then that's a problem.
Boot time is not an issue, it's loading more data, so of course it will take longer. Once it's loaded it's great to use.
Perception is the biggest problem, you use an i5 and i4, of course the i4 will feel poor in comparison because it's what you are used to. It's not that bad at all. I think if it's that bad, just sell it, buy a 4S from ebay.
No, your expecting the world from a 4 year old phone. Basically iOS has been updated, it's a touch slower than before. Big deal! I am happy they just updated it.
Please read my post in its entirety. My father doesn't own an i5, he owns an i4 and has never used an i5. He immediately thought his phone sucked the moment iOS7 installed, and 7.1.1 hasn't made a massive difference. It is more than a touch slower, it's frustratingly so and a chore to use. As for the website loading times, I was talking specifically about data-intensive sites such as a newspaper website. Just doing a quick google isn't mind-wrenchingly slower, but loading up a big newspaper website (which my father does several times a day) takes at least three times as long compared to the i5 running iOS7.1.1
It must be said that I feel the same site would have loaded up faster when my i5 ran iOS6, but I digress.