All the UPS technologies are same.there are two types of UPS are available in market one is online second offline.out put is usually we get square wave in UPS and basic protection circuits like over charging, battery low and short circuit protection available in all ups.
Finally backup time is decided by the battery Ah you are using.usually battery requires 4time more than the usage time to get fully charge if some one tries to charge quickly by tricke charge or may be super charging, your battery life reduces.All the UPS are comes with mosfet modules which is really sensitive and in some cases it bursts in circits and damages other part of circuits.This will increase the service cost.According to my point of veiw this is not the better than the best.,