When an update is this good it deserves a new review.
The little tweaks and enhancements are all great (fine use of the extra screen space for 4" users, pull down list, etc.), but the crown goes to the seamlessly integrated calculator. Incredibly useful; now that its there, its so obvious! The % calculations are great for sales and discounts, especially when they are in a foreign currency. I could go on, but its better you try it yourself :)
Violet.haze about Units - Unit Converter for your iPhone, v2.0