Hey, I'll break it down for you just 'cos I'm nice!
Standard - This is the cheapest and most basic accomodation. If you're looking for just somewhere to catch a few hours kip a night, this is probably best. You simply get a room in a single sex flat of about 5 or 6, a bathroom and I *think* two toilets to share between the flat. Unfortunately, you don't get any kitchen appliances like a toaster or microwave. But you DO get a fridge! Wow!!
Standard Plus - If you want something middle ground, apparantly all standard plus accomodation has been refurbished within the past 5 years (I don't believe them, but oh well!), but it is a lot nicer than standard. You usually get carpeted floors in the hallways, nicer kitchens, sometimes bigger rooms and kitchen appliances included and maintained.
En Suite - If you can afford it, I'd definately recommend going for one of these. All en-suite blocks are two years old or less, and you get your own bathroom with a shower, toilet and washbasin. No need to worry about running across the hall to throw up after a big night out! ;o). The rooms and kitchens are also really nice too.
Studio - DON'T go for these if possible. They're for loners! You do get your own bathroom and kitchen in your room, but it will make you very unsociable! Although brand new and very nice, I'd say avoid!
Any other questions, just ask. I'll be hanging around Broadgate next year anyways as a Karni rep! Woo!