Having purchased a number of those to date (for applications other than windows/doors some being hacks Need Freezer sensor - #29 by PunchCardPgmr) I can say that their "designs are good" being Visonic(Tyco) technology. Visonic spent a lot of effort perfecting highly reliable wireless devices that sip power long before making them "in Zigbee". That said, all this stuff is contract manufactured now and I've found multiple versions of the series. Sage was one, and another manufacturer that slips my mind.
Battery life has been good
(but I DO see a difference between frequently active devices vs not)
range from magnet to sensor is good,
temperature reporting has been good.
Now, all that said...I am flippin fed up of the full concert of devices deployed that are dependent on batteries and I'm resisting the idea of putting battery contact sensors on every window & door.
Given the audacious have-no-fear approaches to breaking & entering these days ...I, rightly or wrongly, figure motions in key internal locations are good enough.....AND THEN spending the money to sense & video intrusion to the property BEFORE the buildings are threatened by any "nare-do-well-ers. The latter might well necessitate some cable runs, posts, poles, and no-see-um positioning of equipment.
