Not commenting on the sound, don’t have them here.

You might want to look at expansion, with just two speakers you are pretty much unlimited in your options. Going to four speakers you have to pay attention to the speaker’s real impedance, not just the general 4 or 8 Ohms usually in the short spec list. If you want six then the Sonos-Sonance ones are the only supported option.

You can work around some of that with an impedance matching speaker selector/splitter but at some cost to the sound quality.

I have used a Bose 251 pair since 2003 with excellent results. This is for a large balcony, so I do not need more than a pair. The issue out of doors is sound dispersion and losing presence, so it is important to get speakers that can be installed as close to the listening spaces as possible, and more than a pair may be needed depending on the target space.

does anyone else have experience with non sonos speaker and amp? Just wondering if I can go with different outdoor speakers then the sonos by sonance brand?

While I don’t have outdoor speakers, there’s really no reason why you can’t get any brand of passive outdoor speakers. Might be easier to get 8 ohm speakers. Sonos has a marketing agreement with Sonance, but an audio signal is a audio signal. 

After reading and watching alot of reviews I ended up going with the polk audio Atrium 8 SDI speakers . I have 4 of them around the pool area connected to an Amp. Very happy with the sound quality. It does make me wonder if I will get better sound out of an Amp and some higher end speakers instead of going with a pair of 5’s. 

I have some atrium 5 (maybe 6) in my backyard and have been very happy with them as well.  Held up for several years now without any issues.  As far as choosing between Fives or Amp+ high speakers, either is a really good option.  It’s going to come down to price and aesthetics.  Is it better to have power cords or speaker wire?  Do you prefer the size of the Fives vs potentially larger passive speakers?