You say you want a "center" speaker, which implies you already have some. If you do, your best bet in getting a center speaker that sounds like the ones you have is to buy it from the same brand as your existing speakers. Otherwise you quite likely will notice a difference in the sound.

If you're buying one of these as a free-standing speaker, it pretty much comes down to which one you think looks better or better matches your budget. I will note that there is a possibility the Kickstarter speaker may not come to be (it would not be the first very-well-funded Kickstarter to go awry).

Aside from that, however, none of us would be able to tell you if more and (somewhat) bigger speakers will sound better. History is littered with the carcasses of huge multiple-driver speakers which were outperformed by two-driver bookshelf speakers. So size and number of speakers or their size or how many watts they use is no guarantee of quality.

I agree, it would be best if we had some idea of what you already have in your system.