Advantages of medicine:
Once you graduate you have a guaranteed job for life, regardless of what happens people will always need doctors.
Once you graduate you "hit the ground running". The NHS give you a salary and there is no messing about trying to get sponsorship for further training or applying for jobs. Infact I think the N.H.S. will even give you a few K per year towards your Uni life in sponsorship.
If you go into surgery and become a Consultant you can earn an N.H.S. salary of 75K top bracket (at the moment). If you do some medical legal work ontop of this (private practice) the sky is the limit and I know of many surgeons who probably pull in double if not three times this in total taking into account N.H.S. and private work.
The only issue relating to this is that the Government is trying to introduce "set fees" for medical legal work, if they succeed the days of charging £150 - 300 for a report are severley numbered.
Eventually you get loads of holiday (something like 2 and a half months a year). I am not sure how much you get when you start out though.
It's a kudos career (trust me, i'm a doctor etc...).
Disadvantages of Medicine:
It's a bloody hard and long degree. You must seriously consider if you have the academic ability in the right areas (i.e. science) before you undertake it.
Once you qualify you will be working all hours godsend for the first few years, probably in A&E every other Saturday night dealing with drunks etc...
Whilst it is an excellent degree it does not really develop your skills for anything else, for example I know some doctors that would be hopeless at anything but medicine!
N.H.S. political infighting and issues relating to pay.
Advantages of Law:
It's a kudos career, Ally Mc Beal and all that
The average starting salary is £18K - £30K (location depending and still an excellent UK salary I hasten to add). If you do well you will eventually end up earning far more and movement up the pay scale is rapid. Apparantly you can expect to add £10 - 15K to the starting salary just three years into legal practice if you are with a good company and they are pleased with you.
Law is a great degree in that once you have qualified you can pretty much do anything (except medicine or some other highly scientific / technical subject). Many companys will see your degree as being a major asset even if you choose not to persue a career in Law and go into business / something else.
Assuming you do the Legal Pratice Course you will always have a "fall back" career in the event that you choose something else and it goes wrong.
Disadvantages of Law:
Whilst it is only a three year degree (unless you do a sandwich) should you wish to be a Lawyer you will then have to do the Legal Practice Course or the BAR followed by two years "probation" in a practice before you become a solicitor or Barrister. This in effect makes it a six year training period. Are you prepared to make this commitment?
Should you choose the BAR (to be a Barrister) you are going to be self employed with no guarantee of work. The average C.P.S. Barrister earns just £20K-£30K per annum (they are currently considering suing to have this raised).
A successful Barrister will earn loads and loads of cash however are you prepared to take the risk?
The LPC/BAR course costs about £7K alone to do despite the fact that it is only one year long. You can try and get sponsorship from a company or take out (another) student loan.
Every year about 6000 people graduate yet there are only about 4000 new jobs. If you do not have a high 2:2 or above you are wasting your time trying to go into legal practice.
Unlike medicine there is no guarantee of a job at the end of the training.
Both careers have their respective stregnths and weaknesses. I am opting for Law myself, mainly because I am not scientifically minded.
You really have to think about what you want to do and where you want to be in ten / fifteen years time before embarking on either degree.
In the short-term (or study period) I think that medicine is a better option as there is various financial help (I think) and you have a guaranteed job once you have qualified, however I feel that once you are in a job there is little to choose from between the two and I *think* that a successful Lawyer moves up the pay scale faster compared to his medical counterpart although in the long term they will both end up on similair salaries.