Like the Dyson V8 replaces the Dyson V7, the Dyson V10 replaces the Dyson V8 (and now, actually the V11 replaces the Dyson V10). Each subsequently newer model improves on what Dyson has learned from it’s years in the cordless stick vacuum business.
The V10 has a larger dustbin than the V8, 20 minutes more runtime per charge, and it has more powerful suction. If you can afford the extra $100-$200 (depending on sale prices etc), then the V10 does make more sense. However, the V8, and even the V7 are still respectable stick vacuums that do a great job.
In reality, Dyson needs to keep innovating to maintain its lead on the competition, and as new models come out, the price of the older versions goes down.
