First of all, thank you very much for your quick answer :D
I am between these two:
M-Audio BX8 D2 - 222 Euro
M-Audio BX5 D2 - 159 Euro
It's a matter 5 vs 8:
Obviously, the bigger the better as long as I would be able to hear lower frequencies and I think I can save some money to do the right thing and go for BX8-D2, because recording is something that might be interested in soon.
However, going with BX8-D2 my concerns are about the the neighbors. I live in a flat, which means I am surrounded by other people living next to me and I am afraid that I am not going to enjoy the BX8 monitors. As I said earlier, I am going to play guitar at bedroom levels. From your experience, do you think that there's going to be a difference between BX8 and BX5 at bedroom level? I mostly play Metallica covers, if that information can help you out upon advising me better.
Thanks for your time,
Panos