How important is it to have ABS on a bike? How much difference would it actually make?

The reason this question is in my head is because I am considering the current crop of VStrom 650s, in particular the 650X vs. the 650A or T. I know that the X is essentially a marketing gimmick, but at the same time it is cheaper than the A & T and gives a headstart with a couple of bolt-ons. But it doesn't have ABS (hence the cheaper price).

Since the X is pitched as more of an 'adventure' bike one might conclude that there is a reason for leaving off the ABS, but I really don't know and that could be more marketing spin!

In terms of my use of the bike it will most likely be constrained to Europe for the time being with the intention of going further afield in the future. It will be mostly for solo riding but with a fair amount of 2-up as well. I've not done much riding off tarmac (apart from a few back roads in Thailand on an inappropriate 400!) so don't know how much of that I may end up doing. This will be the first 'big' bike I will own after my trusty 125 that has kept me going for the last few years.

I tried searching for posts on 'ABS' but the search engine doesn't seem to like three letter search terms and I haven't found anything that covers this topic by browsing, so I'd appreciate any insights or links anyone can provide.