I have an INSANELY nice bike- a $6000 custom Ahearne bike (hey, I've never owned a car, and I saved for many years for it, and I do long-distance international bike touring, and stock bikes don't come in my size..okay I'll stop justifying) and of COURSE I ride it in the rain. I'm of the belief that a bike that can't be ridden in the rain is not a bicycle I want to own. (But I also live in the pacific northwest so it rains 9 months a year.) I work for a bike organization (shop and social services nonprofit) so my bike advice is worth something, I hope.
Full fenders are really important to your comfort and your bike's cleaniness and if it is very muddy outside, I wipe my bike down at least once a week to make sure it doesn't get caked on. If you have trouble with braking, it's likely due to gunk on your rims. Here's a good shop tip on cleaning your rims,
http://www.communitycyclingcenter.org/index.php/shop-tip-cleaning-your-rims/I also recommend making sure you get great waterproof chain lube, it should be marked on the bottle if it is all-weather or not.
I pretty much exclusively ride my really nice bike in the rain but if I'm going out late in a part of town where I'm worrying about it getting stolen, I ride my shittier-looking cargo bike (which was my main ride for years).
Disc brakes are also great in the rain but have a large up-front cost and many bikes don't accept them without work-arounds. I explicitly got cantis (rim brakes) instead of disc brakes on this bike because they're easier to fix in an emergency in a country without specialized bike shops, and the parts are lighter to carry with me on the road. If you're only commuting instead of traveling and have an LBS you trust, they can be a great solution for day-to-day braking power in rainy conditions.