This one is for all of you who are buying XBox points for the first time - I have no idea why anyone else would be reading a review of this! :)
-- Microsoft Points (MSP) --
These points are the same as the Microsoft Points (MSP) that you would buy on the XBox from Microsoft directly (tho worth noting for the complete novice, different to the Achievement points that you get towards your Gamerscore for playing games on the XBox).
-- Cost Comparison --
Points cards usually work out cheaper (depending on postage costs!) compared to buying these directly from Microsoft. Direct, the equivalent cost - at time of writing - is £17.85 for 2100 points (£8.50 per 1000MSP). I have been comparing prices for points on and off for a few years now, and generally stock up when I find them under £15 as they rarely go much below this (you do not need to spend them straight away).
-- Packaging --
As 'Roronoa Zoro' points out, the packaging has now changed (from a DVD sized case with inlay and a seperate card with the code on it) to a thinner card cover with a card encased in egg-box-like packaging. :)
-- Generic Points vs Game-Branded Points --
It is also worth noting that these points can also purchase anything that Lips/Halo/Call of Duty branded points can buy, and vica versa - for example, Halo points are just points, and can buy other games / add-ons for the XBox. The advantages of (for example) a Halo-branded points cards is that it shows a bit more thought if you are giving it as a gift - it just depends on whether the branding is worth the (usual) slight price difference for your gift. Having said this, in some cases the branded points come with added download content, for example, I believe the Halo card comes with a download code for an avatar item.