not going Blose will mean easier upgrades down the road. I believe the stock system sounds fine. It's not like it is a two speaker AM radio in a '72 Datsun. The stock system will play most music genres just fine, but struggles with talk radio. [<-- humor

]. Every system has its limits. don't expect earth shattering bass or perfect stage imaging. It will play music just fine so that when you are singing along to your Sweet Caroline, people pulling up next to you will look at you kinda weird, but may randomly join in on the chorus.
(guitar)
It will be easier to upgrade a non Bose car stereo. The Bose systems always have ultra low resistance speakers than can't be replaced easily and odd amplifiers to match.
I've never been a Bose fan. Not their home gear or their car stereos. The Bose setup in my 2006 Mazda 6, if adjusted just right, is sort of OK. Yes, it was better than the non Bose system from that year but it still isn't all that great. Lots of other factory car stereos will blow it away.
Doesn't come close to a factory JBL system we had in a Lincoln several decades ago. That system, for a factory job, was a thing of beauty.
Anyway, several months ago we had a 24 hour loan of a 2017 CX-5 thanks to Mazda corporate. It had about 8,000 miles on it so both the stereo and transmission had gotten a chance to settle in. The Bose system was significantly better in the 2017 than the one in the 2006 Mazda. It surprised me.
It was far better than the Bose in a 2015 Mazda 6 I had as a loaner. That system just didn't do much of anything right (to my ears) while I had the car. Perhaps changing some settings would have helped but nothing seemed to help the day I had it and I wrote it off as typical Bose gear. It was a loaner, too, so there is no way of knowing how it had been treated over time.
Is the 2017 the best stereo ever? No, but it was up several levels from the older cars. Would you be happy with it? Dunno how critical you are and what your taste in music is. I threw some rock and jazz at it and thought it reasonable. I'm not into metal or EDM and don't listen anywhere near as loud as some folks so it might completely fall apart at very high listening levels. But at moderate volumes (helped by the quiet cabin) it was OK.
If you don't plan on upgrading the factory gear go to your dealer and listen to both systems. If you are planning to upgrade then the non Bose will make the upgrades easier.
Man, I'm getting old. I just wrote something nice about a Bose system.
