I'd say that the GHB2000 is really the baby of the family. I've seen sparkies and domestic plumbers using them where only a limited amount of first fix is required, and for that they are fine - after all the drill is lighter, smaller and more powerful (impact energy, not motor wattage which is sport of immaterial for an SDS drill) than my first heavy Bosch SDS of the early 1980s. But, at £100 there are some heavier duty, and quite frankly better models if you really look around. With an SDS it's a balancing act between weight and impact energy - the higher the impact energy (measured in Joules) the faster a tool will drill into masonry (as well as the larger the diameter the drill bit it will drive) and the better that tool will be for light chiselling, which has become a really useful "must have" in the tradesman's armoury. But, when the weight tops 3kg, though, the tool becomes much more tiresome and wearing to use above one's waist or for repeated drilling (think chemical injection DPMs, for example, where tens or even hundreds of holes are drilled in a session). This is why I personally detest that cheap Titan drill (5kg!). The GBH2000 scores well on weight, but it only generates 1.6J of impact energy - so drilling and wall chasing will be a slow task in harder materials like Accrington brick - slower even than my 18 volt cordless Makita
Against your choice I'll play devil's advocate and suggest a couple of alternatives: there's the Hitachi DH24PX currently at
£90 in B&Q (230 volt). It's heavier at 2.7kg (as opposed to 2.3kg), but it has a far more respectable 2.7J impact energy rating. We've recently bought our apprentice one of these following a strong recommendation from our dry liners (who have 3 of them). I've used it and been pleasantly surprised at how powerful it is, and at least Hitachi have toned down the looks so it's no longer like holding a designer trainer in your hands (some of their tools are quite frankly garish). Secondly, there's the Bosch GBH2-24D at
a penny under £100 from Screwfix which is comparable with the Hitachi (3-function, 2.8kg, 2,7J). I've had a GBH2400 (the slightly downgraded and stripped-out version of the GBH2-24) in the recent past and it was an excellent workhorse. It only went when I decided to go brushless cordless.
So all I'm doing is offering a couple of alternatives in the same price frame.