Which vac?

[hemmerlinj]

The CT15 is the CT Midi without the Bluetooth and the ability to stack Systainers.  Otherwise it appears to be the same dimensions.  The BT isn't a necessity, but it's nice to have.  I use my Midi with my router table that I plug into a different socket and not thru the Ct Midi so having the BT button on the hose at the table is handy.  And it since I also use it to vacuum off dust from my bandsaw it comes in handy so I don't have to wheel the main part of the Vac around the entire shop space(not that it's actually that big of space).  CT15 will be a great choice and save you some scratch.  If it's your first Festool vac I think you'll be amazed at how well it works.  I t really packs the particles into the bag almost like there's little German elves in there stacking everything up to get the most out of the space of the bag.

 

[Steverino]

I’m sure it’s nice to have, but it’s not worth $300. Especially when I could spend $30 on the Fastcap Remote and have basically the same thing.

The Fastcap won't work with newer Festools like the CT15, the electronic switch will not turn back on after the power is disconnected. The older ones with the mechanical switch should be OK though.

 

[Crazyraceguy]

I used a 6 gal shop vac under my back-bench with an I-vac automatic switch for a few years. I got it essentially because of the Domino. The whole-shop main system had a drop for my miter saw and I even had a floor sweep opening in my area, but neither was easy to connect at the bench for hand operated tools. I used this set-up, with pretty good results for quite a while. Then the switch failed. The time I spent waiting on a new one was miserable. It is so easy to forget to turn the vac on, once automatic becomes a thing.
After the fire, while in a temporary facility, I again used a shop vac manually for a few weeks. Even though I had replaced all of the Festool stuff I had before, I didn't buy an extractor.
While the focus of the bosses was to get a new CNC up and running, and we didn't have a panel saw yet, I used the extra space I gained by building a track saw cutting station into the opposite end of my 4' x 8' router table. With the TS55 and a couple of tracks, I was far more independant/productive, but that's when the need for the extractor showed up. Moving the shop vac back and forth wasn't going to get it, so I got a CT26. It made things much simpler. I used it in it's original form for a while, not owning any bluetooth tools, it was fine. Learning about the remote was a game-changer, even though I still don't have any bluetooth tools. I use it a lot for simple clean-ups, but it relly shine with the Kreg jig. When I use the K5 on the bench, I always connect the extractor hose. The remote button is right there, couldn't be easier.
Live without it? of course, I did for years, but I sure wouldn't want to. When you make your living with this stuff and use it all day every day, little improvements matter and this is a big one. It's likely different for a hobby guy though. Plus, what you don't know can't help you. Of course some of this tech didn't exist when I could have used it, years ago. Some I just didn't know about or realize how much it could help improve/speed up my work.
All that so say "it depends", but don't count it out just because of cost. Cheaper alternatives can cost you more in the long run.