Is anyone using swept back bars like like the Ritchey Ecocurve and if so do they make much difference and any idea how much they setback from the center of the stem??

My reach is just that smidge too much and I already have a short stem but would be grateful to bring the hoods back just that bit more.

If anyone has any alternatives of any others I'd be interested to hear them as well.

there is no difference in an even shorter stem vs swept back bars if the hoods position is the same. A stem is generally cheaper as well

Have you given any thought to a zero setback seat post?
I have had the same issue. After adding a shorter stem I felt I was still just a touch stretched out. I tried a zero setback seat post and combined with the shorter stem it worked out great.

The reach of a handlebar is measure from the center (at the stem) to furthest part of the curve, so the slight sweep of those bars is not going to affect the reach...unless the reach is shorter than your current bar. The sweep back is there to help with ergonomics while on the flats (i.e climbing).

The Ecocurve has a reach of 83mm, so if your current bar has a longer reach, then it will help. Other options for short reach handlebars are the 3T Superergo (77mm) and Zipp 70 Ergo (70mm).

I've had to go the other way with a majorly set back seatpost to get my knees in the right position so I don't get any pain in them or my hips (both replaced and 6 knee operations) and strangely enough seems to pretty much coincide with KOPS ...

It's the only bike I've ever been measured for before ordering / buying and it's the only one I've had problems with and I think it's just a poorly fitting bike ... although it is my 1st drop bar since I was a kid

Cheers for that and makes sense ... I#ll go measure my current ones and have a look at the ones you've suggested and compare them.