Has anyone upgraded the stock speakers for high end ones and are driving them with the stock head unit and no amplifier? Please let me know what you think about the sound vs the stock speakers. I have two sets of Boston Acoustics Pro series and I do not know if I should install them or not.

 

If you do some searches you will find numerous posts. I replaced speakers in an Acura that was Bose equipped. A definite improvement. Even though the replacements (Infinity Kappa) were 4 ohm, and the original Bose were 2 ohm, the volume never suffered, because the Inifinitys were much more efficient.
I don't find the Bose in my G THAT bad, that I have bothered, yet.
It's not a priority for me like it is with my home system. But for some car audio is a very high on their list. If you have a list like that, I would recommend new amp and speakers (maybe your Bostons) and professionally installed unless you have that kind of experience.