I love that site, too bad the guy allowed D2Items to sponsor it because it USED to be linked from the Arreat Summit in their files section. After it went to D2Items, they dumped it like a hot rock.
That site is great for all chars except sorcs, poison necros, and high elemental damage characters. It doesn't take into account the enhanced damage the facets now give or the upgraded items like Mav's set for cold damage.
For me the game is a science. BIG surprise, eh? Back when the patch first came out I blindly made characters not knowing which way was best to distribute points. Thought it was fun, but then I got serious and went back to planning my characters.
If you play PKs/PvP or want to build high damage/effective characters, planning them is the only way to go. Field trials are a different matter.