I purchased two Philpis Onis phones 4 years ago, after 2 years they started to fail. Philips were not much use as they wanted the base station and phones to be sent to them for repair which would have left us with no phones. I was persuaded, due to the cost of repair, to purchase a newer model the Onis 200. The base station is compatable with the earlier Onis model so I purchased another one of these to have an extension on the main line.
Now the new Onis 200 has started to fail all it shows on display is the word "Failed" when trying to connect to the base station. New batteries have not cured the problem nor has the suggestion of removing batteries and power to the base for 15 minutes, then reconnecting helped. The extension does still work thank goodness. Philips as usual were of little help apart from the above suggestion, asking for the whole system to be sent to them again for repair leaving us again without a phone.
Final score is 4 phones purchased 3 failed, one still working.
I would suggest that if you are in the market for a DECt phone you should give Philips a wide berth.