As I say most every time, a value score based solely on money and measured benchmarks isn't all-inclusive since not everything about a board can be measured. With a similar price to the OCF and similar performance numbers, it's not surprising to see them essentially tied for value according to this math. But we need to look deeper.
In this review, the Asus Z97M-Plus has been compared to the ASRock Z97M OC Formula. What's the verdict? In terms of CPU overclocking, the Plus takes a more refined approach. ASRock uses brute force by throwing a bigger VRM at the problem. Asus gives you more detailed control over voltage and power delivery. The result is roughly the same. For those who want fine control over their CPU voltage, or have more temperamental chips, Asus offers more than the competition. The strange Turbo Boost behavior might be a turn-off to some, but only those who won't be manually tuning their CPU on this board.
Unfortunately, RAM support on the Plus is lacking. It excels at DDR3-2400, but it simply can't reach higher frequencies. This is great if your RAM can't go above 2400 or if you don't want to spend extra money on premium modules. Those wanting the absolute fastest RAM system should look elsewhere.
My biggest disappointment in the Plus is in the small details. The OCF added value with a premium audio chip, Killer networking, a fuller I/O backplate, more fan headers and SLI support. The Plus doesn't have any of these. In terms of actual features, it's more comparable to the ASRock Z97M Pro4, a board that sells for less. The extra money spent on the Plus gets you an M.2 slot and more refined BIOS control. Whether or not that's worth it is entirely up to you, the buyer.
I want to stress this isn't a bad board. It's actually quite solid in consistency and features. I would have no complaint about quality or reliability if using it in a personal system. What matters is the price. At higher prices it simply can't compete with something like the Z97M OC Formula, which offers more hardware for the same money.
The Z97M-Plus is like a better overclocking Z97M Pro4, but with an M.2 slot. That makes it worth about $15 to $20 more than the Pro4 in my book, but not the $35 Asus originally asked. But with Skylake and the 10-series boards now out, these prices are completely relative as the 9-series boards will likely see end-of-life price drops. If you can find this on sale in the $100 to $110 range, it's a great deal.