Yes, they have different spec. From things I've read the newer ones with the painted headstock have hotter pups than the others.
If you decide on the V4 than try a few out, this goes for any bass really. Some will feel and sound better to you than others, but the consistent is that you know all will be well made and spec'd.
All the CVs hardware is made in china, and most will agree while the Wilkinson hardware may also be made in china, it's of very decent quality.
If we knew what style or kinds of music you want the p bass for, we can help narrow down your search?