OK, this may be kind of long, but hopefully will help you make a good decision...
Like many others, I bought my refurbished Ooma Telo VoIP through woot! (in my case it was July 2012 or about $500 ago...) I liked the idea enough that I bought one for my 80+ year old parents at the same time. (We set up the one for my parents when we moved them to a house next door.) It is seamless if you hook it up to a phone set they are used to using, so there is VERY little learning curve once it is hooked up.
Things I love about the Ooma system:
1) good quality sound
Things that can be an aggravation (especially if you are 80+ and not too tech savvy)
2) low cost (about $3.75 a month locally in taxes and fees--great if you are on a fixed budget)
3) 911 capable (very important if you are 80+)
4) can connect it to the phone jack to 'energize' the whole house with one unit allowing multiple outlets to be used for wired phones, or being able to set your base set with answering machine somewhere other than near your router/Ooma, such as in the kitchen.
5) free long distance (extremely important when you move 600 miles from your friends of 60+ years)
6) cheap overseas rates (important when you have a lot of family overseas.)
1) may need to be reset if there is a power outage or internet outage. This could be a real annoyance if you have frequent 'momentaries' from the power company in your area.
2) will occasionally (VERY infrequently) drop calls.
1) hook your router and the Ooma up to a cheap UPS system. This will bridge the gap during any power outages up to a 1/2 hour or so and eliminate the need to re-boot the system most of the time. Good for cheap peace of mind, plus if the power is off but not the internet service, you can still use the phone until the UPS battery dies. **NOTE** if you are using a wireless set-up the base unit will HAVE to be plugged in to the UPS for this to work or you will be dead in the water...
2) IF it does go off for longer, you can always use the power button on the UPS to restart it and get all the parts (router and OOMA) talking to each other properly with just one button to push.
3) equipment is easily placed in a closet/under a desk etc. where the occasional blue blinking lights won't be such a concern for an older person with early onset Alzheimer's or dementia.
4) If having the possibility of being out of service for short periods of time is a big concern, buy a pay-as-you-go plan cell phone for emergencies. You can get one for about $100 a year with some plans. If you live next door to elderly parents you are concerned about, consider a cheap (<$35) walkie-talkie set.
Overall, I love both my (and my parents') Oomas and wish I had switched over long ago and as already mentioned, this is the best price on this unit so far. I am even considering buying one as a 'back-up' in the event one of the ones I already have goes belly up...
Hope I didn't ramble on too long...