I used to use twin 100w Ikelites on my Ikelite housings, and i loved them because they charged fast and had ZERO hotspots. However, the ni-cad battery packs that you need to use them are frickin' huge, and you will have to buy better arms for them than the sticks that pass for arms that come with the lights.
They are quite bright thought, that's for sure. Way brighter than any light I've personally used.
Probably the biggest plus to using Ikelites is the fact that if the light breaks down, you have about a 99% chance that if sent back to them, Ikelite will either fix or replace the light with almost no questions asked, free of charge. They stand by their product like nobody in the business.
yes, there are smoother lights, lights that allow you to adjust the intensity of the beams...there are better lights in general. What it comes down to is what you need out of your equipment, and how much you're prepared to spend. Ultimately like any other piece of equipment.