How big of a speed difference will be noticed with a 100-200 MHz overclock? I am going to overclock my 600 MHz to around 700-800+. Nothing too big of a jump, and don't need any help either. The question I'm concerned about is what kind of performance does this slight speed increase yield?

Will it make any big difference that can be noticed? Note that this is simply overclocking the CPU and changing nothing else with my configuration in idle.

I have heard some argue that raising clock speed alone doesn't really guarantee better performance, since microarchitecture and bus speeds are what determines ultimate performance. 

For example, on Super N64 emulator I am getting like 7 frames per-second running Super Mario 64 on my current 600 MHz. Will the increase make any immediate difference? How can this be properly estimated by incremental clock speed, etc.? Will some apps run faster, will more background apps do their job better, will I execute/boot faster, etc.?

Basically, I want to know what to expect within the range of aforementioned clock speed increase.
It's impossible to tell, the effect of overclocking varies depending on the specific software and hardware. 

However it likely won't make any notable difference if you're only getting 7fps in a game. Overclocking is highly unlikely to make an unplayable game improved to the point where the game becomes playable, except in very rare circumstances such as with games that have a speed budget to decide whether to frame skip and your phone is just barely below the budget which causes it to consistently frame skips and the extra processing power manages to push it to be consistently below the budget.


  some argue that raising clock speed alone doesn't really guarantee better performance, since microarchitecture and bus speeds are what determines ultimate performance.


Performance is a complex thing, but one thing for sure is that CPU is rarely the bottleneck in many applications. Booting, for example, is IO bound, the bottleneck of booting is how fast it can marshal data from the persistent storage to RAM. 

In short, you'll have to try it yourself.