FWIW I have the Omron and I also really like their app+sync. It just works.
I compare it to measurements at the Dr office and so far it's been pretty accurate.
While in recovery at the hospital they gave me Metoprolol, half a dose every the morning, and after half a year BP went down from a slightly worrying hypertension to just were it should be.
(hospital tends to not worry too much about side effects or pricing, so my PCP just keeps me on that prescription)