The main disadvantage of the Vara is not that it's heavier in general - but it's top heavier. The Strom is lighter, sportier, faster. The Vara is even more comfortable on long rides, but a bit unhandier in the city.
The Strom is not ugly, I rate it nicer than the Vara when looked at it from a few m distance. But from close it looks a little like put together from various pieces, while the Vara looks like 'one'.
The Strom's engine is somewhat more a source of joy. It's more punchy and dynamic. The Vara is smoother, and has better low rpm roll. Can easy ride her at 2000 rpm, because they gave her a balancer.
If Suzuki had done a little more effort for the fork, the Strom would have unquestionable the better suspension. But put overall, now the 2003 and later Varas are some of the best stuff you can get in terms of suspension. But they are actually both quite high level.
The Vara's engine is proven an utterly reliable beast, since many years. The Strom has to prove that still, but it looks like it could last long as well. A German magazine did a 50,000 km test, and dismanteled the engine. Found no issues.
The Vara has lesser warranty issues. It has issues, but there ARE more small niggles with the Strom. I read the Vara forum since 1.5 years.
It is logical that more Vara's are sold 2. hand in UK, because the bike is in the market since 1999, thus more are on the road.
I like my Strom. But I do not need to be brand blind.
So now let it bleed.
Regards
Peter