Hi Bordyn! I think it doesn't matter what programming language you are using. I agree with Peter. I have bought Raisonace RKIT (C, macro assembler, code compressor etc.) and I was afraid to use C because of the code size. I didn't want to use an additional memory for new project. But I've decided to write WHOLE program in C to ensure that it couldn't fit into 8kB memory (it is machine controller). Now I have been impressed of code size. It is really working very fast and my program is less than 8kB... The most valuable for me is, that I have wrote program in 2 weeks!!!
If you are writing code for I2C appliction, C should work as good as Assembler, I think (if you are not using 100kHz crystal ;o) ). It rather depends on your programing technique than on language you are currently using. By the way: I2C doesn't need so precious timing.

Regards,
Jacek