I think you’re analysis is correct. The sub should last longer than the playbar, and both have at least 5 years minimum support.  I do think there is some reason to hesitate on buying the Sub right now though.  There have been vague rumors of a new redesigned coming out, possible a new ‘Core’ Sub in the $400 range that might make more sense bonded with the Beam.  But there isn’t any really strong evidence to that.  There is also the possibility of future discounts.  When Sonos does offer discounts, Christmas retail season mostly, the Sub is often on sale.

Yea I could use the Sub for playbar 2 later on. And the core sub for the beam

I’ve not seen these rumors for a “Core SUB” other than requests from customers here on these forums. Can you point me at any other sources, please?

Here are the sources: 

• https://en.community.sonos.com/home-theater-228993/new-sonos-sub-and-atmos-surrounds-6819118
• https://www.theverge.com/circuitbreaker/2019/1/10/18176624/sonos-dolby-atmos-reddit-survey-sonos-core-sub

The post is over a year now so it could mean that Sonos is finishing up their Core Sub and Atmos Surround speakers. Maybe they could release that summer or holiday 2020 with the Playbar 2 

Most interesting, thank you very much. 

Just as a counterpoint, it’s also possible that the reaction to that survey pointed to the fact that it wouldn’t make economic sense for them to develop one or both of those items. Surveys are to gather information, not promises that those items are in the process of being made. 

We will have to see if anything comes from it.

I’d not hesitate to buy a Sub, I just bought two myself.

If the price is an issue you could keep your eyes open for a deal on an “open box” one or a Sonos sale.

Another option good for 30% off is to trade-up a Legacy Sonos device. It will quit working and you have to agree to properly recycle the unit to qualify.

I just bought a sub myself, but I'm wondered to keep it or not. I know the sub is very powerful, but do you think the software would stop it from working?

No.  Stanley wasn’t suggesting that Sonos Subs are going to stop working, he stated the legacy device that’s traded in would go into recycle mode and stop working.

To those surveys, no corporation sends out a survey about something they already have in the pipeline.  They survey for possible projects, not existing ones.  Matter of fact, the last survey I recall was for a Windows Mobile app, and the result of that survey was a Windows Mobile app is a non-starter. 

I can’t see any reason for the current Sub to quit working for the foreseeable future, it has plenty of memory and only needs very simple software since it is a slave device, not a primary player. The Sub isn’t eligible for the Trade-Up deal so there is no possibility of having it disabled accidentally.

That 30% is a sweet deal:

Sub with Trade-Up: $489.30  

Sub cash price:        $699.00

Not much a lot of memory compared to modern device. 32mb vs 1024mb, I know it's a slave device but I think it would only going to last max 5 years

Why?  What future functions do you foresee the Sub doing besides playing a single channel of bass?

But if they want to be in the same 5.1 set they have to have the same firmware update, which will require the same amount of processing IMO

I’d disagree. While they need to be ‘aware’ of all types of speakers, they’d only need a subset of the full control package, since you don’t need to ‘tune’ in to any streams, or know about local libraries. 

Maybe IDK, i just hope it last like 10 years that would be best

I’d be very surprised if it didn’t last 15 or so years with full support like my original collection of Sonos devices. Even past that point I’d expect it to continue working but maybe not get any new features.

Keep in mind the thing that caused the initial Sonos memory problems was a big growth spurt in the Linux kernel, that isn’t likely to happen again due to design changes since then. Adding Sonos features will eat up some memory but as was said, it is just a Sub, it isn’t likely they can find a lot to add to it that will take much more memory.

Reading a bunch of stuff by folks that make a living by scaring folks into reading their articles is usually a bad idea. Paying attention to folks that read the above and believed it is also bad. Then you have the butt-hurt bunch that are gonna kill their kitten if Sonos doesn’t give them something more for free. Trying to filter out the scary stuff from the truth is not an easy task.

I like Sonos as a company and I like their equipment but I’m not in the :they can do no wrong camp.” I’m still ticked at the CR-100 EOL. I wish Sonos had done the Legacy split much sooner and let me keep my CRs.