The 1723 Center S is a 2-way MTM and so far we haven't seen any of those that are any good, so I doubt it. But hey, I'm willing to be shocked, and I like Arendal as a company obviously since I own their products. Still wouldn't touch it without a review.
You have to go to a few thousand bucks to get most known definitive upgrades. Very few 3-way center speakers have been measured so there's many unknowns remaining. But it's probably worth mentioning the Kef R3 on its side, which is definitely a step up, but looks a bit odd. The R2C has great directivity, but needs its on axis fixed with EQ. Not sure I would bother with either unless I was using a Kef system to start with. Which I would, the R-series is one of the best options for a midrange $$ multi-channel system.
The Revel C208 is really good and has better directivity with a better controlled woofer-midrange crossover and less high frequency narrowing, but that's $2000. It's also quite large with a near-12" height.
There are various bookshelves that probably would sound better depending on how loud you need to play, like the Revel M106 or the new
Ascend Sierra LX(low sensitivity, though). In general I'd say you are better off using an identical bookshelf or one from the same lineup as your L/R if physically possible, instead of a dedicated center, as most are just compromised designs made to fit in a height restriction.
Right, it might come back, but until it does, it's not a useful recommendation, because nobody is waiting around for a year to buy a cheap center speaker.