x5 for me too. My zigbee mesh is far stronger and faster with generally much bettery battery life. My Iris v2 motion sensors (and sylvania) are some of the rockstars of my setup. I did end up adding some xbees(search on this forum) which then let me actually see my zigbee network and what was going on. IF I could easily switch out my zwave for zigbee I would. But most dimmer switches are zwave and lots of other zwave devices. So for now I'll have both. I've been moving away from those dimmer switches and using the Lutron Caseta/RA2 stuff. I'd be VERY happy if I just ended up with Zigbee/Lutron and no zwave some day.
All that being said...that's for MY HOUSE. No idea why my zwave just sucks so bad. Others on here clearly have the exact opposite experiences. Zigbee doesn't work for them but zwave does. RF frequencies in a house with other electronics and construction is simply something you're going to have to find out in YOUR house.