i gotta be honest i have used the DCS and found that its not so dustless more like less dust. company i used to work for bought 3 units and were down to 2 in less than 8 months. i can't see spending that kind of money on a piece of equiptment that isn't gonna last. and i have to agree with gary edger and buffer only still use a bag on the big machine.

It all depends,

When the first bona 110 came out, the company I was with ordered one. I was extremley skeptical of it from the begining. I couldnt see him justifing close to 9k with the new buffer and dcs (I thought it would be better to just give me 9k lol)
He got it, and the first job was beautiful no dust anywhere, we didnt hang plastic or anything.
Because of that unit and customer (Who we used the dustless for free) she called everyone she knew and told them all about it, within one week we had 9 dustless sandjobs to do.
After about a month or so (maybe 5 jobs) the unit began running poorly, we could only attach one piece of equipment at a time (or dust would come out the other tools) So we began using the ceno vac for the edger, and shipped the unit to bona for repairs. It came back a week later and they said it was just dirty. It worked for one job, then right back to how it was before.
We sent it back again, they sent it back saying it was working properly. It wasnt, but they didnt seem to want to help us at all.
So we used it on the big machine only it sucked up alot of the dust, but not all. We tried duct taping the hoses to the hummel, still had a small amount of dust.
The edger and buffer we used the ceno vac, it is perfect for those applications (I use that set up now.) But every "dustless" job we did had some dust. It wasnt much, but more than I thought their should be. It looked like the customer didnt dust for a week or two (on tables ect)

So when I left to do my own thing I looked into every system, the place he bought his bona from was my first stop, as soon as I said bona to them they quickly steered me away, ststing that the original ones had a motor issue that no one was willing to accept the blame for, so there were no repairs avaliable ect.
He showed me the oneida and let me use it on a job.
I was extremely impressed, the retro fit stack for the hummel is what every dustless sytem should have (IMO) no duct taping anything, a filter on the machine (sure its a little hard to see around at first, but it gets the job done right, and it actually makes the system look professional (IMO) every customer asks what that is, and I tell them oh thats the HEPA filter. Its a good selling point)

I folow the directions on cleaning the filters to a T, after every job I blow them out with the compressor, and every 300 feet of sanding I crank the handle o the filter. Ive sanded 1000's of feet thus far, still extremely happy with the set up. Its not 100% dust free, but it is 99%. My customers cant even tell that I was sanding after I am done, Even had one floor I had to trowel fill. I hung plastic for that, there wasnt any dust on the plastic when I was done.
I actually think the dust that does get in the job sites is from me, I empty the unit outside and naturally with a 33 gallon bag of dust its going to get on you, I brush it off or blow it off with the compressor, and off the unit, But I always miss some spot on myself lol.

I only use it on the hummel, and sometimes its hard to justify close to 5k for a vacum for the hummel, But alot of the other tools I have are just as hard to justify, until its actually needed. I have made the money back for the system just on the jobs I have gotten with customers who are adiment about using a dustless company.

I just tried out the Bona 110 system. When I went to the Bona School they did not have the 110 system. I couldn't see dropping the 30k or so for a trailer. So I tried to come up with a system of my own. I use this Jet dust collector.

www.toolbarn.com/product/jet/708626CK/?ref=base

It pulls better than the bona 110 system. I use the hose that would come with the Bona Trailer I think that it is a 2" or maybe a 2 1/2" hose. I use my blue dcs vac for the edger and the buffer though. The dust collector is usually set up outside on the porch I use cardboard in a window and vent the hose though that to allow for the hose in the winter. The bona 110 did perform better than the blue dcs vac for edging. Though only marginally, both were totally adequate.

I probably put together my system for the big machine for $1500.00. Then use my vacuum for the buffing and edging.

I saw this as a much better option than biting off Bona's 30k trailer system. Also with the filter on this dust collector I can run it inside when I have had to. Still no dust.

We run a Bona Atomic (trailer) system, as well as two portable systems. The portable systems are both Latta Equipment...excellent machines. The Atomic is also awesome, it's a bit expensive to maintain...but all in all a phenomenal investment.