….we're no longer in the pre-standlight days. You'd nowadays have to deliberately search for dynamo lighting without standlight. Why would you do that rather than choose one of the many easily available, brilliant (pun intended) and efficient dynamo systems with standlight?
Rear light standlights I think are a good idea and (IME) when they go wrong they don't usually cause the whole light to fail.
However unless your front standlight meets the requirements of any of the applicable standards, then legally speaking it might as well not be there. In terms of being seen, a feeble glow-worm might seem to be better than nothing but it may just give you a false sense of confidence. In terms of actually being seen, if you are in the beam of a car's headlights and have reflectors/reflexite fitted, a typical standlight will hardly register amongst this lot. So I have my doubts about the true value of such a thing.
If you have to make a single right turn in a journey you would be as well (or better) off with a simple (and legal) blinky rather than a standlight. Come to think of it I would vote for front standlights to be blinky not steady, as that way they would be more likely to produce a legally compliant amount of light and would probably contribute better towards you being seen.
I also note that lamps with standlights often develop odd behaviours, eg not switching on a low speed unless the capacitor is charged, and decreased levels of brightness at low speeds until the capacitor is well charged. It is most certainly not the case that such a thing comes without potential drawbacks.
What I don't have any doubts about is that the standlight is the thing that is most likely to go wrong in many front lights. Look inside a typical light and there is no concession to the fact that the light will see a lot of vibration; both the supercapacitor and the choke are usually mounted in such a way as they will simply fatigue off the board, sooner or later. I'd far sooner that they spent money on things in the light that make it better and more reliable, not worse and less.
I always carry a backup light of some kind and I use this for thirty seconds whenever I have to navigate from the bike to the back door and/or lock the bike. This means I am always sure that the thing still works, without which it could be nigh-on useless.
Regarding bracket breakage; this is (obviously) more likely to happen if the lamp is heavy. I dunno how much extra the standlight/senso/DRL gubbins weighs but it is some extra weight rather than none. I've never seen a wire-type bracket break with a simple, lightweight lamp mounted to it. You can avoid the lamp housing itself breaking by simply choosing a lamp that isn't too heavy and mounting it on a bracket that will move when it is clouted, rather than a stupid 100% rigid mount. Obviously the lighter the lamp is, the less tight the bracket needs to be, and the less likely any real damage is to occur. Strategically placed spring washers in the mountings can help with all this.
Regarding wire breakages; I prefer not to use zip ties because they concentrate the bending strain in the wire at one point, and if they are done up tight enough to stop the wire from moving in service, it may not pull through when tugged. I normally use tape instead; if taped correctly the wires don't flex at one point and will pull through if they see a hard tug. A Brucey top tip is to have a little excess wire doubled up under the tape; this means there is excess for repairs and it also means a hard tug will just cause more wire to miraculously appear rather than lead to a breakage.
I have always arranged to have wires such that they will pull off the generator rather than break first; e.g. by having connectors that just pull out (I ran for about 25 years with such a setup; it never gave me a moment's worry). In more recent years (with a shimano hub) I have just used the centre part of a shimano connector; this pulls off the generator quite easily and also allows the thing to be fettled/rewired very easily should this be necessary. However if the wires are a bit flimsy, you could lose the plug off the end of the wire when the wheel is out I suppose.
On the subject of accidental damage I recently saw a (almost new) hub generator that got mangled into oblivion when a simple bungy cord hook got dropped into the front wheel. It got dragged round with the wheel and smashed the connector block to pieces.
It is very easy to spend a fortune on lights and still end up with a system that is a bit shit. However with a bit of thought and application you can have a system which is inherently more reliable and it doesn't have to cost a fortune or be a PITA to live with either.
cheers