Like others have said, it depends on what you are trying to do with the tractor. On the other hand, and this is based solely on my experience with the three pieces of equipment at work with loaders, some equipment does feel underpowered.
We have a Kubota
BX2200 w/ bar tires, a Kubota
L2850 w/ 4wd and bar tires, and a Case 580M with 4wd. We got the BX because of its small size, allowing us to use the loader in tight areas, mostly for snow removal. Since we have it though, we use it quite a bit, whenever we need a loader. Most of the people who use it feel it is underpowered. We've found it is difficult to dig into loam piles that have been sitting for a while. The
L2850 has much less difficulty with its larger bucket, and the Case will just about push the pile over if you wanted it to. There are also times when you can load the bucket of the
BX2200 full of material, and it isn't able to lift it much past half its total lift. The
L2850 has no such problems with the same material and a full bucket, and the seemingly overpowered Case also has no problems.
We do tend to be hard on equipment, and its clear that the
BX2200 isn't really the tractor we should be using, as it really isn't designed for what we use it for. But just based on its ability to use a loader, I'd have to say it seems underpowered, or at least not quite matched right.