501 vs 503?

[blando3]

I own the 3221 Wilderness Systems tripod with 501 head and can't stand the fact that it doesn't have a ball head for leveling. So, I'm looking at the 351MVB2 with either the 501 or 503 head. Any suggestions on why I should pay $100 more for the 503 head? I really don't know the difference between these two, so if anyone can give me a few pointers, that would be great.
Thanks!

 

[SomewhereinLA]

I have both, and they look exactly the same. One can support a slightly heavier camera... Not sure it's worth the money... I use both with an HVX, 35mm adaoptor, Marschall monitor, matte box and FF. both work fine.

 

[Bayne]

I just picked up the 501 with the 351 legs...love it. I use an M2 with my DVX and I dont have a problem at all..

 

[3CHIP Productions]

I'm loving the 503.