I'll add two things. One, Yes price is high but they have Samsung leds so they are really bright and quality is very good. Less pricey ones may have quality and brightness issues. Also, the built in resistor prevents hyperflash and in many options that cost less, you have to buy it separately.
Second, the manufacturer recommends continuous use of not more than 8 minutes because they heat up ... In normal driving it doesn't go beyond 3 to 4 minutes. But I just thought I should let you know. You can't keep them on for extended periods of time...like on motorway.
I have been using them for over a year without any issue though. And the crisp on-off is an absolute treat to watch.