Just for info I had the rear spring of my 2005 1200GS uprated by MCT in Stowmarket so that my wife and I could tour France with vario luggage and not compromise the handling/suspension. Unfortunately our combined weight still overpowered the suspension (it was about 1" lower that friends on identical bikes) - must have been that extra box of tissues she insisted on packing (ahem) - Since we got back I have been in touch with them again and they have told me that they can put on an even stronger spring but it will overpower the standard rear shock so will also need to upgrade it and have quoted me £533 for an Ohlins including fitting and the stronger spring. Not sure how this compares with what you might find elsewhere but I was told that the equivalent WP would be more expensive and in his opinion not such a good option. The company is pretty well known to my bike club (EAMG) and Darren there has a very good reputation and about 30 years plus experience.
Just for info I had the rear spring of my 2005 1200GS uprated by MCT in Stowmarket so that my wife and I could tour France with vario luggage and not compromise the handling/suspension. Unfortunately our combined weight still overpowered the suspension (it was about 1" lower that friends on identical bikes) -
No didn't feel any harsher but very conscious that the bike was sitting way down at the back and so very nervous about hitting bumps too hard and had limited ground clearance ( I actually got my toe down when cranked over) I also couldn't use the side stand.