I can't talk about WHY something is better without knowing your personal stats and gear.

ArP vs Haste - depends on spec, how much ArP you have, your trinkets, etc.
Expertise cap - depends on spec, depends on crit, depends on hit, depends on gear
Mongoose vs Berserking - depends on gear, usually Mongoose.
Black Magic - bad.
Rupture - gone for good once you have decent gear or need to keep a bleed up for HfB
ArP soft - easy enough with heroic ArP trinket, scales well

2pc T10 bonus - It's good, how good depends on your current gear. It gives Energy which has a variable value depending on your own personal setup.

95% of rogue itemization questions come down to such impossibly complex math that either a piece is clearly better (ilvl 200 vs 245) or it is too close to call and requires a spreadsheet. Some is itemized well, some is itemized poorly, but whether or not you should use it is entirely up to you. Well for one person is bad for another. Guys at the crit cap don't want items loaded with agi and crit and value hit and expertise, while rogues below the ArP softcap should focus on gemming that purely.