The rundown:
Leicester - Have a rich history of winning ***les. Many suspect because of "under-hand tactics". Passionate but humourless fans. Great stadium in a horrible city.
Saracens - Current champions. Bloody difficult to beat, can play attractive rugby if they want to. Fans mix from really-really good (old school fez heads) to complete bellends (mostly the recently converted soccer fans). Horrible stadium in a horrible city.
Gloucester - Excellent fans (with the odd bellend). Excellent stadium in a reasonable area. Very good rugby team. Never win anything.
Northampton - Pretty much the same as Gloucester. Fans tend to laugh at themselves slightly more then the Gloucester lot.
Bath - The most Amateurish Pro team in the world. Crap stadium in a good city. Would win a lot if they could maintain concentration.
London Irish - Can be a good team, buckle too much under pressure. Fans play the victim card. Clean (if boring) soccer stadium on the arse end of an industrial estate.
Quins - Another COULD be good team if they could maintain some consistency. Some fans can be snobbish (it's not just a stereotype). Good stadium in a good area.
Wasps - Crap team living off past glories. Fans range from good fun to miserable. Surprisingly good (if dirty) stadium in a crap area (another at the back of an industrial estate.
Exeter - Home fans are surprisingly miserable, the travellers are a good bunch. Rugby is okay. Stadium is alright (for the back end of beyond). Probably will improve. Good local pubs.
Sale - Some excellent fans (and on the flip side, Olyy!). Horrid stadium. Steve Diamond means a horrible brand of rugby. Relegation fodder.
Newcastle - Horrible brand of rugby. Can't comment on Kingston park (never been as they refuse to play any time but on Friday night). Like to play on plastic pitches. Fans are passionate and good singers - All 12 of them. Relegation favourites.
Worcester - Fans got a bit up their own arse before the relegation, the year in ND1 should have got them back to their old form. Sixways is a great stadium, but on the back of an Industrial estate. Rugby remains to be seen.
Leeds - Great stadium with cheep beer. Good fans. Horrid rugby.
Hope that helps.