solicitor and PITF question

hi folks, just a quick question.

my accident claim has been going on for the better half of 6 years now. finally in December we agreed a settlement figure. Having spoken to my solicitor he advised me that as I am on state benefits and the amount I have been awarded is above the allowance before my benefits are affected that I should take out a personal injury trust fund. Anyway, as I am a little curious in dealings like this I looked them up online to find they are legitimate phewwww
The figure was agreed in december as I said to which my solicitor said it would all be sorted out by the middle of January. I called on the 19th and he told me that it should be arriving any day now, then when he receives the cheque he will call me in to sign some forms for the PITF and jobs a good un.
So, to my question. Is it common place for the solicitor to hold onto the settlement for a while as I have been warned by a few friends that this happens so the solicitors company can gain interest off the settlement.

Having dealt with solicitors befoe in other matters I am aware that they do drag their feet a lot but I am reluctant to keep calling them as I feel like I am a being an annoyance to him. Also, does anyone know roughly how long it takes to set up one of these PITF's?

thanks