The Nanolux I looked at was hardwired to the socket. I didn't care for that. Most other ballasts I looked at had a plug. Most hoods I looked at had a plug. A small thing albeit.
No cooling fins? Again, no big deal but it made me raise an eyebrow.
And, this is just my personal opinion but I don't like the idea of a dimmable ballast. There has been talk in all directions about this and, although, I don't see anything totally wrong about it, I just didn't like the idea.
My ballast is not dimmable but rather, selectable. It doesn't have a 70%/50%/etc dial. It has a 1000w/600w/250w dial. According to the owners manual, it is not intended to run a 1000w bulb at any setting other than the 1000w. If you run the 600w setting, use a 600w bulb. 250w setting, a 250w bulb. I kind of like this better than the percent dial and dimming a higher wattage bulb to a lower setting.
Again, that's just my opinion and there are good arguments on all sides of this topic.