Couple of things I experienced with my student loan.
I attended uni twice, so had 2 seperate lots of student loans. One in 97 - 98, and again from '03-'07.
The first set were sold off, which was pants. Meant it wasn't taken off before tax, so I paid tax on my earnings, then paid off the loan after. But it was a relatively small amount.
Second lot were huge. I could borrow somewhere around £4k per year, and as I was repeating 1st and 2nd year, I had to pay fees for these years, so I borrowed maximum amount each time.
When I graduated, I got a pretty low wage, and managed to defer payments a couple years. Then I paid a small amount each month for a couple years. Then I got laid off, so deferred again, but got a job in Holland. I didn't pay anything, and was never chased down. I was there for around 2 years.
Now I work back in the UK, and have started paying it back in earnest. Last I checked it was over £16k. I guess I'll get an update soon with the financial year being over again. But I seem to be paying something between £200 - £300 per month, so I guess it'll go reasonably quickly. Bonus is though, when it is paid, that'll free up a couple hundred quid a month, so might go for a new motor, lol.
With respect to mortgages. It did make a MASSIVE difference to the affordability of my loan. And reduced my borrowing power by well over £100k. Luckily we didn't max out our borrowing when I was working away, as we only just managed to change our mortgage that time, between the reduced borrowing power and the reduced value of the property.