It depends on you way of thinking.
I believe electronic ignition is the way to go. Just look at all the cars on the road, most have electronic ignition. zero have mags (maybe a few veterans) and only older classic cars have contact breakers and most of those have electronic conversions. How many do you see broken down at the side of the road with failed spark?
I have had a Lucas rita on my Velocette for 30 years and you get full high intensity spark even if you kick over slowly, does not get weaker when hot. Majority of classic bikes that are difficult to start can trace it down to a mag.
New electronic ignitions can be cheap and are reliable, newer ones less than £20 such as
http://www.ebay.co.uk/itm/Powerspark-45D-ELECTRONIC-IGNITION-KIT-for-Lucas-43D-45D-59D-Distributors-/360508264952?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item53eff791f8 so viable to carry a spare. The expensive part is the mechanical magneto replacement, but I bought a complete lucas RITA replacement A10 kit on ebay for £80, so they are available without paying £200+, there is one at £60 on ebay at the moment with single spark but easy and cheap to change to twin.
http://www.ebay.co.uk/itm/Lucas-Magneto-replacement-electronic-ignition-kit-Triumph-BSA-Norton-Vincent-/330842117269?pt=UK_Motorcycle_Parts&hash=item4d07ba1495The downside as mentioned is the need for reliable electrics. Well if you don't have a working dynamo or alternator, lights etc then maybe you should not be using your bike anyway? If you have the later alternator instead of a dynamo then you can normally get a good spark with a flat battery on kick over, I can on my Velo with alternator conversion.
Magnetos have been around for a long time and many find they work well. Later capacitors increase reliability but don't forget the old 60 year old bearings, flaky points and brushes. If you are half way round the continent and the mag fails??? .
Originality is important to some people, I think the mag replacement points holder looks right (was fitted as standard to some British bike when mags dried up in 1969-70, Velo Thuxton being one.) But I want reliability and consistent high intensity spark and good starting so my Lucas competion magneto will stay on the garage shelf .