Piki,
my experience with electronic ignition:
On my CB750 K7 I have points and Hondaman's transistorised ignition.
I think this is the best option, keeping simplicity and boosting reliability by lowering current via points. In case of failure of electronics you just reconnect back points and you continue riding (in less than 5 mins), no tools needed.
Advancer is kept. Precondition is points in good mechanical shape, preferrably Honda genuine TEC
http://sohc4shop.com/catalog/product_info.php?cPath=23&products_id=32On CB 550 K1 (yes, I have older type of carbs, not PD) I have Boyer Brandsen Micro Digital in combination with stock coils.
This solution removes advancer, it has "advancing curve" pre-programmed in control unit.Works w/o any issue, I have it since last Aug, bought from one member here as used, just wanted to try. Not sure if and how much it increases power consumption but I suspect it increased.
Voltage regulator - normally I would keep stock one, it is reliable, CB500/550 four charging systems are designed "on edge" for normal riding, e.g. does not charge under 3000 RPM with headlight (H4) on. Electronic regulator does not bring better changing compare to good stock mechanical regulator.
In my specific case I observe some issues in higher RPMs with stock regulator ( I tested 2 already, both works great on my 750 K7), when charging voltage drops in >5500 RPMs, leading to less voltage during longer trips (riding >100 km/h). I tested also combined reg-rect from Electrex that did not have this issue but I was unable to fit it on place under side panel w/o modifiing some part of bike (unit too big).
So I decided to go for unit from Ricks
https://ricksmotorsportelectrics.com/OEM-Style-Honda-Rectifier-Regulator-10_100 that is reported as fitting into place and reliable. Just placed order last week... Will report once installed.
=> If your regulator is charging properly, keep it, no need to change.In your case: I would measure power consumption/charging with points and then measure again after you replace by electronic ign to verify it. If no big increase, no worry, it will work fine.
note: avoid putting aftermarket lower resistance coils (3 Ohms), those will surely increase consumption. Known "issue" for Dyna S ign and coils, there are many posts about..