I'm just going to do a very subjective good/bad list for Yorkshire and Humber foundations school.
I am personally in West Yorkshire so this list mainly applies to there.
1) You apply for F2 linked jobs. This means you know what all 6 of your rotations will be for the two years right from the start which frustratingly isn't the case for a lot of deaneries. This is quite a big deal as it means you can plan your life a bit more - where you will be living and working, career (e.g. did you get that 'vital' rotation for the obscure specialty you want to work in), love life, earnings.
2) This varies from year to year but for some reason people don't apply to Y+H as much as other deaneries despite it being great for all the below reasons and having more than average the number of jobs. This means you are more likely to get in (again you can roughly plan the next two years of your life before March as you can be more confident you will get in). It also seems to be the case that the average overall scores of applicants seems to be lower so you may be more likely to get the job you want - again this varies.
3) Particularly in West Yorkshire deanery, every hospital placement is commutable from Leeds centre so no fear of living right in the sticks if that's not your sort of thing.
4) Its cheap up north - and not at all grim.
5) Good combination of large(ish) cities with everything you need but easily accessible to nice countryside areas like the peak district, lakes and dales.
6) Direct train from Leeds to London! And because you don't live in London you can afford to enjoy it!
7) In West yorkshire at least (and I think in the others too) everyone has at least one year in a DDH and one in a inner city teaching hospital. I recommend DDH first - generally smaller so quicker to get your head round, and probably have more hands-on experience due to less support (arguably a bad point).
1) You have to rank the 3 separate deaneries - West, South and North East - before ranking jobs. This is only annoying as its a further delay in knowing where you will actually be placed but I think that ranking process only takes about 2 weeks or less to come through.
2) Kind of far from London - although see point 5 of the goods!
3) Slightly worse weather.