Hi gregfreefaller,
just wanted to add my opinion as well. The most important when it comes to the carb is, that the carb is
fully functional AND set up correctly for suit your engine.
Below you can see the pics - one from Dellorto and one from Keihin - about carburettor operations mode. As you can see, the carburettor system is complicated, since all jets and needles in the system overlap each other in function. The carb-manufacturer developed the system the way it works for a good reason and Dellorto and Keihin carbs are working fine in many bikes and engines.
I fitted a Dellorto on a 2002 FE 501 and on a 2004 FE 550 engine. Works fine for me - as long as your setup fits the engine. I also have a Keihin, which I don't like so far since the setup is not suitable for the 501 and the 550. I think it will also work nice, when the jetting is correct.
FCR carbs have more parts and are more expensive than Dellorto ones. FCR fits Bergs 2004+ by default... when using a Dellorto on a 2004+, you need to make it tight fit to the intake rubber boot.
My opinion about Lectron. I just checked their website - the website looks nice - but the carbs don't (Lectron Details Views pdf attached). To me the carbs look more like scooter carbs - but that's not my concern.
- They're new on the market
- They do not really advertise a reference bike - you can see pics of 4-stroke engines with their carbs - but the 4-stroke carb is not available yet?
- Currently they only advertise 2-stroke carbs
- 4-Stroke carb release date is postponed until end of may 2017.
So me personally I don't like a $400+ experimental system, especially when you check the setup procedure with their "fuel ratio tool" (video:
https://www.youtube.com/watch?v=DWarCP8aC6A), which is another $160.
When you have problems with installing / jetting for a keihin you can always ask guys in this forum - if the Lectron needs adjustment?
When they can proof that their new carb is good and well tested and suits the Berg's, I also want to test one. But I don't want to be their release-test-candidate...
I would spend the money on the Keihin and the correct setup and you'll be fine.