Frogg Toggs, Put them on before you hit the rain! Look at the cars coming towards you, when you see wipers and lights on and shiny wet cars, time to stop and suit up.
They Pack in nice never leave home without them, Over 75K miles of Street riding 10K last 5 months. I've seen my share of rain sleet and snow.

You can maybe buy better rain gear but none that will be there when you need it as in ALWAYS. I get the best price on them at Shadetree.
http://shadetreepowersports.com/ I don't use the Bag they give you to pack em, I rather lay them in my saddle bags as a 'Liner' of sorts to keep stuff from 'rattling around' when needed I just pull em out, they take up less room this way. (Flat)
Occasionally mist them with Camp Dry or Heavy Duty Scotch Guard type stuff. (Adds color back and more water resistant)
They Will Melt as said here, but I repair by putting quality duct tape inside and then on outside so that where the Hole is the two pieces of tape stick to each other, cut the patches with rounded edges such as an oval and they will stay on forever, Use RV glue by GOOP for smaller holes but whatever that stuff touches it sticks to like a weld, so back repair with cardboard until set or you will have one legged trousers!
I use plain old rubber gloves with them, the kind you use like at work, black, not dish gloves, the kind with a cloth type coating inside. I wear over the sleeves and wind keeps water going right direction.
With 'Gators' You will be 100% water tight. I never experienced a leak at the neck but then I wear Full or 3/4 face helmet and a shield.
At auto supply you can get small squeegee that they use to spread body filler, the rubber kind for spreading the final filler, this makes a good tool to wipe your shield and it won't scratch it.
I use a Mil Spec Vest when in the rain. Good idea all the time but as visibility is less in rain, even more so.

This whole story about my 1500+ Miles in 2 days Bike ride here.
http://www.westpaxterraclub.com/Forum/viewtopic.php?t=1884
If you seriously get in the rain, try to find a truck to follow as his stopping distance will be greater than a cars, the truck tires will lay down some great tracks to follow and disperse any puddles in the lane and allow you more time to react to what might go on in rainy riding. Plus, a Truck Driver sits much higher out of the mist and can see further ahead than You or cars, so you sort of go off his reactions, if he taps the breaks, get ready, somethings going on.
Your tires do make a difference, i like my New Avons! Dunlop I hear is good too just stay clear of slipstone or be more careful when you have them on. It was a scary 8K miles with them on.
my 98 Cents worth. Sorry so long. But I had to chime in as a Bike has always been a daily driver for me here in Ohio.
MC