If you're predominantly doing commercial work, being VAT registered is a good thing. And you can voluntarily register even under the threshold.
Here's some simple accounts.
Turnover - 10,000
Expenses - 2,400 (£2,000 plus £400 VAT)
Profit £7,600
Register for VAT
Turnover - £12,000 (£10,000 plus £2,000 VAT)
Expenses - £2,400 (£2,000 plus £400 VAT)
Payment to Inland Revenue = £2,000 of VAT charged less £400 of VAT paid = £1,600
Profit £8,000
So, if you only do commercial you're better off being VAT registered.
Based on the above examples, tax credits would make up earnings in both cases to the same minimum amount or equivalent. Only one of them will have the headache of filling in VAT returns 
OK.
Turnover - 70,000
Expenses -
16,800 (£14,000 plus £2,800 VAT)
Profit £53,200
Register for VAT
Turnover - £84,000 (£70,000 plus £14,000 VAT)
Expenses -
£16,800 (£14,000 plus £2,800 VAT)
Payment to Inland Revenue = £14,000 of VAT charged less £2,800 of VAT paid =
£11,200Profit £56,000
£2,800 for filling out a simple (and it is simple) form four times a year. Not what I'd call "foolish".
Now make a cocky comment on that.
Vin