On £2,000, you will get an extra 2,000 x 5.85 cents, which is $117. Well worth having in my view: nearly enough for two park tickets, or a slap up meal for 4!
 
Corporate FX will give you a competive rate if you want cash delivered to your door, or travellers cheques etc, but always the rate will be as good as or better than other sources. They can also transfer your dollars to your US bank account by BACS, (takes 3-4 days) which at present is free, but is likely soon to be charged at £10 or so by their bank, Lloyds, or CHAPS (24 hours) for a current fee of £20.
 
One of the very best things about them is that they never talk down to you when you phone them and display your ignorance of the system! They are very friendly and matter of fact about what they can offer, and will tell you what they think the $ rate will do in the short term, although obviously there are no guarantees!
 
If you are changing a large sum and want to achieve a particular, higher, rate, then they can ‘log’ your rate and will only make the exchange (automatically) if the rate goes up to that level on the currency markets anywhere around the world. You can also ‘forward buy’ to protect the rate over a given period, and only pay a deposit at the time of 10% of the total contract value, which will be deducted from the outstanding balance which is due the day before the value date. Of course this costs more because you are effectively borrowing the money for that period. However, I did do it when buying the original purchase money, and luckily it paid off!