I've long been an opponent of the "lumen race", and honestly you can ride and survive with very little light. Back years ago, I used a tiny LED hiking light for everything but the tough downhills in one of the mountain bike endurance races in Pisgah. It couldn't have been more than 50 lumens. Yes, it certainly was slower with so little light, but it was manageable, and after 12 hour of racing a little slower isn't such a bad thing.
In my opinion, there are really two factors you have to take into account. The first is how much light do you need to be able to ride at close to daylight race speed assuming that’s your goal. The second, if you ride with other people, or are racing in races where you'll be around a lot of other people, how much light will they be using. That matters because your eyes will adjust to amount of light around you. If you have significantly less light than the folks around you, your light will be drowned out.
On the first point, and this varies somewhat person to person, I can get close to daylight race speeds with 200 lumens on the helmet and 200 lumens on the bars in a solo setting where I don't come across brighter lights that mess up my night vision. I'm a big proponent of having nearly equal amount of light bar / helmet. If I do ride with a brighter light, I use it on the helmet. Having a brighter light on the bars causes your eyes to adjust to that and then the effectiveness of the helmet light suffers and it becomes harder to see around corners. That doesn't necessarily mean you have to use the same light bar/helmet, but I wouldn't overdo it on the bars and I would tend to run the bar light at a brightness setting that matches the helmet. Also, it’s not just lumens, beam patterns for helmet and bar is also relevant.
On the second point, and this is the one that drives me a little crazy, the problem is that the average person on group night rides and at races tends to have around 800 lumens total these days. I find that I have to match that to be able to approach daylight race speeds. I think that's where the 800 total lumen recommendation is really coming from. Unfortunately this will likely continue to escalate. But I have noticed that once you get into the 800 lumen range, it doesn't appear to be as big of an issue if people have somewhere brighter lights. But when people start showing up with 2000+ total lumens I suspect it'll become a problem again.
As far as Dinotte, L&M, and NR. I've worked on all three lights. You can tell someone passionate about riding and his lights designed the Dinotte’s. It's not that L&M and NR lights are bad, and it does vary somewhat model to model, but they have shipped some lights and chargers that seemed to have been rushed out the door a little too quickly. But all three brands are good quality. You’re in a funny situation where Dinotte isn’t a lot cheaper. In your case, you should just pick based on which you like best and price. Look at the details like mounts, chargers, battery mounting, and beam patterns. I generally like L&M designs better than NR, but I really hate how high the SECA series mounts on the helmet. I’m not a fan of the beam pattern on the Stella.
I don't have anything against individuals building and selling lights, but I tend to think they cater best to someone who has the knowledge and would like to build their own lights, but simply doesn't have the time. When you get into this space, you don't really know if the person is going to be around in a couple of years and you often get a light that still needs a little tinkering to get the way you want it. To an extent, you're picking a person as much as you are a light if you want support long term. You also need to look at things like the accessories for these types of light. Do you like the way the mounts work. Will the mounts work well on your helmet or bars? What do they do about chargers? Are they providing a charger of their own design or passing along something like one of the questionable Chinese made chargers. If you've decided you don't want to get that from Magicshine, you shouldn't turn around and buy the same thing from an individual builder.
