Part of backhoe loaders' popularity is based on the fact that they fall in the middle of a range of digging and loading equipment, bringing more power than compact machines without the expense of full-sized excavators. You should consider whether a backhoe loader is the right choice for the bulk of your digging and earthmoving needs.
For smaller jobs and increased flexibility, the combination of a skid steer loader with a standard bucket and a mini excavator can sometimes work faster than a backhoe loader. It can be cheaper to buy the two smaller machines than one backhoe loader, but you'll need an operator for each one and you'll have more transportation and maintenance hassles. These mini machines are most valuable in very crowded conditions, and recent trends have many contractors replacing at least one backhoe with a mini excavator.
For high-end digging power, full sized excavators are the best choice. These massive tracked machines are only worthwhile if your application calls for ongoing digging: building foundations, for example. However, their size makes them less useful on cramped construction sites.
Backhoe loaders fill a very important middle ground, where having an excavator and loading bucket on one relatively compact machine is essential. They're also much better at moving around large job sites or between sites you can drive a backhoe on the road if need be, while excavators and skid steers have to be moved on trailers.
Choosing a backhoe loader
The first consideration when choosing a backhoe loader is how deep you'll need it to dig. Full-sized backhoes can usually reach down 14 to 16 feet; compact backhoes can typically dig around eight to 10 feet deep. For full size machines, 14' depths are by far the most common. Compact backhoe loaders are great if most of your work is less than 10' deep they're less expensive, easier to maneuver, and easier to transport than full-sized backhoes.
On the other end, reach can be important: if you need to load dump trucks of a certain size, make sure the loader has an appropriate lift height to do the job. Lift capacity is similarly important: you'll need to know how much weight your machine can handle. Keep in mind that capacity varies for the two tools loaders typically have much greater capacities than backhoes.
One spec that you shouldn't put too much emphasis on is horsepower. Engine horsepower doesn't directly impact the capabilities of the attachments: digging and lifting are powered by the backhoe's hydraulic systems, not the engine. You should be aware of horsepower ratings when comparing different models, but don't let them drive your decision.