High output bulbs used to be illegal in the UK, but not any more. HID lamp light output verses wattage made the law worthless as the values used did not relate to modern lamp outputs. The law is know that they must not dazzle oncoming traffic.
100/90 bulbs should in theory give a better light, but in practice may not do as the increased current they draw can result in more volt drop in the wiring.
In addition the additional current draw may stress the wiring and switchgear, resulting in their early failure.
If you are intent in fitting these bulb then you must fit relays for both main and dip beam with heavy duty cables to stop volt drop.
A better way to go is to fit HID lamps, but be aware that in the UK most kits do not conform to EU and UK construction and use regulations, in part because the reflectors are not designed for them.
For more info on HID lamp use in the UK see
http://www.phoenixautobulbs.co.uk/tp/hi ... tion-2012/The following article appears to indicate that the use of retrofitted HID kits is ilegal in the USA as well, but I am not familiar with the intricacy of the USA legal process or laws.
http://www.hella.com/produktion/HellaUS ... proved.jspJust my ideas
Keith C