My first machine was a Kenmore in about 1976 (still in high school). My second machine was a Pfaff 7550 in 1994. Other than picking up a sweet Pfaff 1471 for $50 as a backup machine, I haven't bought a machine since.
New machines are relatively unreliable compared to older machines, to my way of thinking. The electronics are getting cheaper and cheaper.
If your machine is in good working order and it does what you want it to do, you have absolutely no reason to upgrade. Don't let them talk you into it. One reason I fear taking my machine to a sewing machine shop is I worry they'll break it, forcing me to get a new one. I trust them like I trust used car salespeople.