These expensive reels are marketed in Japan but are available in the US only on line, I believe. I think Amazon has them. They can cast much farther because the spool can spin much faster, and the computer can then optimally brake the spool when appropriate to eliminate backlashes in most all circumstances. Kind of like ABS for reels. Anybody tried these? Wonder if they're really that good. Maybe some day mid-priced reels will have a computer chip.

They have quite the following, guys getting addicted to that whine.

 

A number of folks on the board have DC reels. I have 3: Calais DC, Calcutta TE-100DC, and Metanium DC. Like Blue said, the DC "whine" is addictive.  

The digital control is just another kind of braking system. It generally has an advantage in windy conditions compared to other braking systems. DC reels might, or might not, cast farther than other braking systems, depending on the iteration of the digital control system that you're looking at and what conventional braking system reel you are comparing it to.

Most of the DC reels are indeed fairly pricey...but one, the Exsence DC, was very affordable (at least it was in the recent past when the dollar/yen rate was more favorable for us).

At present, if you want a new DC reel, you are indeed looking at JDM sources. The only two DC reels that were USDM (the aforementioned Calais DC and Calcutta TE-100DC) have both been dropped from the U.S, line-up since those models were discontinued in Japan. It remains to be seen whether Shimano USA will bring in any of the newer generation DC reels from Japan.

Here's another thread to add to your reading list: 

 

Shimano makes a version of the scorpion with the DC feature. It's basically their entry level and can be found south of $200 in good, used condition. 

The scorpion dc doesn't have the cool whine though.  I have an exsence dc, but I got it while yen/dollar exchange was more favorable.   It's a killer frog reel.

It's a dangerous purchase, and you're opening a door you can never close again lol.  

I have casted an Excense DC in the past, and do think it's delightful. As far as owning one goes, I probably won't until we see the yen drop favorably for us again.

I compare a DC reel's whine to driving a car with a loud exhaust. The sound is fine if it's yours, but a little annoying if it's someone else's.