This.
I'm not sure what the point of using sugar cubes is. It's more work, less consistent, and generally a total pain compared to batch priming. Aside from some rather hilarious claims about sugar and bacteria in this thread, I really do have to ask what value the OP is hoping to get out of doing his priming the most difficult and least controllable way possible.
I remember batch priming being intimidating to me as a newbie. Now after I've done it, I can't imagine what I would possibly gain by an alternative method.
A newbie has been taught to fear infection and oxidation and here you are transfering gallons of beer into an open bottle only to immediately move it out of the vessel immediately. That seems, the first time you wrap your mind around it, somehow wrong. You've just scrounged together your first set of equipment and you need yet another piece, a bottling bucker, dedicated *only* to hold the beer for five minutes on bottling day?
For me it was the transfering and siphoning that scared me. My first situation was artificially weird though. I had a fermenter with a spigot but for a bottling bucket I used a large pasta pot. (It was a 2 gallon batch). I transferred and mixed the sugar very easily with the spigot and tubing but now I had to get it into the bottles with a racking cane and tubing. (I hadn't realized then what a fantastic thing a bottling wand is nor did I realize that a bottling wand and tubing can be used in conjunction with a spigot.) I had to start the siphon with gravity, a scary and intemidating pain in the ass. (Now it's just a pain) I had to fill bottles with a tube *spraying* the beer out with the sole control being pinching with a plastic clamp that turned out to be a piece of junk.
Of course the lesson I *should* have learned was get the proper equipment. A bottling wand is worth its weight in gold and bottling bucket with a spigot is nice. (Although without a spigot of you get an siphon *with* bottling wand *and* the clips to make it stable, you'll be fine.)
Anyway, from *this* side, I see that batch priming is *nothing* to be afraid of a the best way to do it. But without proper equipment or fear of the one extra step I can understand the appeal of direct bottle priming.
Also the biggest complaint against bottle priming is the inconsistency. Pouring a teaspoon of sugar into each bottle is ineffecient and inaccurate. However this wouldn't be the case with carb tabs (ludicrously expensive) or sugar cubes which would be utterly consistent. However depending on the type of beer it may be under of over carbing a bit.
The way I see it, sugar cube carbing would save you about 20 minutes of time and make cleaning a bit easier. It'd be hard to argue that those advantages are worth it but... well, there's a certain ingenuity to it that appeals to me and I find myself curious to try it once.