To everybody that is going to buy one of those cellphones above, you should know that if you buy a 2GB memory card, your phone will become slower, but it still work, slower. Plus in a Z3 while listening music, battery may be consumed like in 4 o less hours with full charge, I dont know how much does the battery lasts in a Z6 because I dont have one.

The Only Reason It Will Become "Slower" is because it has more to load from files from the TF. I Do Use A 2gb on the phone and only had to wait a second longer to load pictures but thats it.