There are very little benefits these days for typical contractors being LTD. The financial benefits get smaller every year and depending on what you are doing and how many customers you have there is the risk of IR35. The flat rate VAT is virtually pointless as you make about £10 in every £10k it really is miniscule.
As a contractor through a limited company you need to organise your own pension and make provisions for times you cant work (sickness / holiday / out of contract). There are still some benefits, but they are nowhere near what they used to be compared to 10 years ago.
depends on the contractor. My gf fell into one where she could claim a decent percentage as a flat rate. I did a quick calculation and even if she kept every receipt for everything she wouldnt even come close to that much VAT. That meant about 3-4% vat gain on a turnover of over £100k so over £3k per annum for her for free. Plus she didnt need to keep any of her receipts for the VAT inspections either.
Plus a lot depends on your rates. My gf was earning substantially more per day than she ever did through PAYE to cover pension, holidays & sickness