I cant say about RC sail boats, but RC helicopters are intense. Once you feel the thrill of flying one and putting it down safe you will be hooked for life. Nothing and I do mead NOTHING can compare to the thrill. I have a few very fast RC cars (OFNA 9.5 PRO) and they are just lame now.
The concentration and skill in flying is what is all about for me. After set down when all I can hear is my MAH carbon mains spinning down and my hand are shaking from excitement with that sweet smell of burning nitro hanging in the air, I wouldn't trade that for any thing. Not to mention the huge feeling of accomplishment when you first run up that engine and hear the blades start to bite into the air as you add pitch. One second it's sitting on the ground a whirling noisy package of death, and the next it's leaps into the air all vibration and noise are gone. It just seems to hang from the sky on an invisible thread.
Speed? Ha! I thought my OFNA car was fast....The evo in a full power dive is blistering. The response is so great I just think and the heli goes. It is almost like it becomes linked with my brain. You get some strange looks pulling a six foot "toy" helicopter out of a car trunk at the lake tho.
I have seen the nice RC sail boats out on the lake and they seem neat. My problem with RC boats of any kind is failure. You will be looking at a swim to get you boat back. With the a heli you can (almost) always land.
They even have floats for them so you can land and take off of the water!
Sorry for the OT but just had to chime in on this one.
My thoughts are if you want it, buy it.
Oh yeah please heed the advice give by Tommay and buy the biggest most bad a$$ one you can afford, and when you get bored with it shelf it and buy a heli kit.
One thig to be said about RC toys is the can always be fixed. I have let cars sit for 10 years with no issue other than dead battery's. Just charge em up add fuel and go.
FREA EVO 90
Old shuttle Z now converted to ZXX
Not my best landing ever...