Yeah, there is no such thing as 40SW +P, and the Buffalo Bore site is definitely not a place I'd go for any reference to load standards. Can you load any cartridge you please to 10% over the standard pressure and call it +P? Sure you can. And if you don't measure your pressures and take the *statistics* associated with those measures, you can load to 12% or 14% above the recommendation and call *that* +P, too. Heck, folks sometimes refer to 10mm Auto +P, too, and 10mm +P "is not a thing", either. I've always felt 180 gr was already pushing it for 40SW anyway--there's very little wiggle room there in seating depth without potentially moving peak pressure a lot further than you maybe think you are.
The sweet thing about 10mm, IMO, is you can load it *down*, reduce pressure, and get 40SW "+P". That's a direction you can go and not worry if your firearm was built to take it...or not.
Since there IS no 40SW +P recommendation, to me that means no manufacturer of 40SW-chambered firearms has wrung their products out for 40SW +P use. Of course we assume all major manufacturers know about safety factors and overbuild to accommodate variation in ammo. It's the allowable variation that SAAMI helps to define, and in part that's why SAMMI exists, why standards exist, and why folks might choose to comply with those recommendations--to specify what that variation can/should look like. Offering such a product with such a label in the first place (a 40SW +P) is further confirmation, to me, that certain ammo manufacturers don't really give a hoot about complying with those standards or supporting them in name and deed. Just my opinion.
As for "is it just as good"...I think the question is "can I get a 180 gr bullet to go about as fast?". I can safely load a 9mm Luger bullet to "go just as fast" as comparable bullet can be safely loaded in 10mm Auto. One at the high end of published loads, the other at the extreme low end of published loads. Is one just as good as the other? Are they comparable? I think it all depends on your personal definitions of comparable and just as good.