You cannot find reviews on the Anex Air-Z as that is one completely new stroller. It is not a bad one, it sports a cool design, a nice padding plus a switch reversed option for the smallest babies (watch out, the center of gravity there will not be the most comfortable to push, most probably), and a very nice low weight. On the other hand, just by looking at it, I can tell you it will be much better for your second on the way but way too tight, short in space for your 2.5 years old. Even if it states a high weight capacity, the seat is simply short and narrow to expect a comfy push with a larger toddler, that is really one thing to understand here. Still a cool option, and if it fits your budget and your eldest is on the tiny side, it could work well for you.
Other than that, also check a Cybex Beezy or a Koelstra Buggy Gen which are not expensive that much, either. And don't expect much in terms of suspension/terrain ride from any ultracompact, otherwise you'll end up a bit disappointed, the more so the more affordable the buggy is going to be.