Is the VDS actually worth adding to my setup?

I've had mine running a few months, so here's the honest take. It does dry like any heated box, that part is the same as what you've got. What it adds is holding several spools dry at once while they're already plumbed into the feed path, and on printers that support it, a spool swap happens mid print without you standing there. When roll one runs out during a long job, it pulls from the next one. That's the actual difference, not the drying itself. For your situation it sounds like you'd get almost none of that value. You print mostly single color, you manually swap without it bothering you, and your current box has handled PLA and PETG fine. If moisture were silently wrecking your prints you'd know by now, and it isn't. A lot of people who bought one were coming from nothing at all, just airtight tubs with silica, so for them it replaced a whole setup. You already have the half that matters for your printing habits. The people I'd say it genuinely makes sense for are the ones running multi color prints where an automatic runout swap saves a failed ten hour job, or anyone with a damp garage or basement humming along year round. If neither describes you, the promo price is still real money for convenience you don't want. And the emails are doing exactly what they're designed to do. The discount exists to make you solve a problem you've already solved with the gear on your shelf. If you ever do get into multi material stuff, that's the day to buy, and there'll be another sale by then. There always is.

Been printing since the days we were rigging food dehydrators with a hole drilled in the side and calling it a filament dryer. Worked fine then, works fine now. The old ways stick around because they solve the actual problem, which in your case is allready solved. One thing I will say is keep an eye on those PTFE tubes where they bend near the printer, they wear out and cause feed issues that people blame on everythign else. But as for the VDS, skip it til you actually need it. Marketing emails are free to ignore.

Bought one last year and honestly it's just more stuff to fuss with now. You gotta swap the desiccant, keep an eye on the humidity readout, clean the feed path when dust builds up. My old dryer box just sat there and did its job. Also mine hums loud enough that I notice it, wich gets old during overnight prints. Only time I've been glad I had it was a nylon run in summer, but that's like two weeks a year for me. If you're sticking to PLA and PETG I'd skip it and spend the cash on filament.

Reading this as someone who's basicly the opposite of the OP, still using a plastic tub with silica packs and hoping for the best. So this thread is kind of answering a question I hadn't asked yet. One thing I'm still fuzzy on though, does the feed path stay dry all the way to the printer, or does filament soak up moisture again in the tube on long runs? I print nylon sometimes and it always seems fussy no matter what I do, so I can't tell if a setup like this would actually help or if I'd just be adding another box to worry about. Total lurker here so go easy on me if that's a dumb question.

Update: the mid-print spool swapping is what sold me, since I do run some longer jobs that burn through more than one spool. Still on the fence though because of the maintanence gripe, desiccant and humidity checks sound like chores my current box never had. One thing I still can't tell from here: once the filament leaves the unit, does the feed path stay dry all the way into the printer, or does it pick up ambient air along the tubes like mine does now?