Pros of Liquid cooling?

Hey guys,

I have always ran air coolers in my builds, currently got a mammoth cooler master cooler, it cools my 4790k pretty well, but I am getting a bit bored of the size of the thing. When I dust out my PC every month or so and re-apply thermal paste every few months, it's just a HUGE pain in the *** of a job that I don't look forward to doing due to how big it is and how much of a struggle I have all the time getting it off and back on again.

So Liquid Coolers like the H110i and H105 etc. look like the more manageable way to go. My case has an unused radiator space with vents at the top and I am assuming that's where the fans screw in, and just plop the actual square thingy majig onto the cooler. Which should mean easier to pop off to replace thermal paste in the long run right?

So what are the cons, if any, to liquid coolers? Are they reliable? Long lasting? Risky? If any at all please let me know.

Also if you have the time, which one is best to grab from these 4 :-

H110i - Corsair Hydro H110i GT HP 280mm Liquid CPU Cooler - Ebuyer
Cooler Master - Cooler Master Nepton 280L 280mm Radiator/2x140mm Jetflo Fans CPU Liquid Cooler - Ebuyer
H105 - Corsair Hydro Series H105 Extreme Performance 240mm Liquid CPU Cooler - Ebuyer
Fractal Design S36 - Fractal Design Kelvin S36 Hydro Performance Cooler - Ebuyer

Cheers