Where should the tip of your racket be when you hit a backhand drive? The answer has changed over the years. Historically, players could choose to keep the racket tip down (so that a line between the tip and the handle would parallel the ground), or with the tip pointed up to 45 degrees upward, or somewhere in between. At the higher levels, however, this has changed.
When the tip is more down, you get more pure power, as well as the potential for more topspin. It's almost like having a second forehand, as demonstrated by such past stars as Jorgen Persson and Jim Butler. However, it's generally not as quick, it's generally not as consistent unless you back up more, and it's harder to cover the middle.
When the tip is more up, the shot becomes quicker and flatter, generally more consistent, and you cover the middle better, but you lose the potential for extra topspin. You can still hit the ball pretty hard, but it basically becomes an aggressive blocking backhand. A good example from the past would be 1971 World Men's Singles Champion Stellan Bengtsson, who hit his backhand with the tip somewhat up.
At the beginning level, it's probably easier to hit the backhand with the tip at least somewhat up. It's also easier for kids, since it's awkward hitting with the tip down until you are tall enough that your elbow hangs naturally well over the table. (Otherwise you have to lift the elbow up to do this.) At the intermediate level there's probably no major advantage to either way - both ways work, with the tip down players more powerful, the tip up players quicker.
At the higher levels, however, with modern souped-up sponges, the regular backhand has been mostly replaced by either the backhand loop or a very topspinny backhand. (The definitions aren't clear on this as the distinction between the two isn't as clear as it used to be.) To create topspin, you need to drop the tip down so you can accelerate it through the ball. And so nearly all top players play with the tip more down, creating extra topspin in their shots.
So which should you use? If you aspire to reach a high level, then unless you naturally play a quick-blocking style backhand, I'd recommend keeping the tip a bit more down, and develop it as a serious weapon, with both speed and topspin, perhaps as strong as your forehand. Some players attack with the tip down, but raise the tip some when blocking; experiment and see what works for you. If you do decide to develop your backhand into a topspinny shot that dominates like a forehand, look into using sponges that are designed for this. Trying to do a modern topspin shot with equipment designed for the game as it was played in the past is like racing in the Indianapolis 500 with a Model T. (For help with that, ask your dealer, or a coach or top player.)