Hi. Yes, your credit rating will remain shot ( but you don't want credit anyway

). But, your lives will be your own again. Your income will be yours to do with as you wish and, if you win the lottery or Great Aunt Matilda leaves you her millions, it won't have to be paid to your IP.
On the other side, you will be slightly reducing your pension for the rest of your life to counter a few years IVA payments, so it might cost you more in the long run. Always take professional advice when tinkering with pension pots.
If you do go ahead and draw down a portion of your pension for a F&F you will need to get the agreement in place BEFORE you draw the money down --- otherwise it will be payable into the IVA as a windfall and will be lost to you.
My opinions are merely that .. opinions based on experience. Always seek professional advice.
IVA Completed 23rd July 2013 .... C.C. 10th January 2014