Well i havent played anything besides CIV4 and the war lords expansion, but i have a feeling that CIV5 is going to be the firaxis version of HOI3. Its gonna be buggy and slow and basicly suck. Bunch of people are going to 'love' it and the oler players will stick with CIV4/CIV3/etc. Basicly whatever game you start playing at first, whether it be I/II/III/IV/V is the one you will most likely stick with. CIV5 is gonna crash and burn.
So yes in a way, CIV I could be better than CIV 5 if that person thats playing it likes CIV I better. It has to do with the person.