I used the silicone. Did not use the heat shrink clamps they recommend as replacing these later is a nightmare due to restricted space (you need to cut them off!). I'm using the spring clamps that came on several heater hoses from the factory, but had a slight leak I attributed to one clamp not being fully on the silicone hose (green, from NAPA). I'll know if this was the case when I check for leaks in a few weeks.
If you are really really particular then with silicone hose you will use lined stainless steel worm drive clamps that incorporate a constant tension spring. The spring compensates for the fact that silcone hoses don't bond to the metal pipe the same way that rubber hoses do. The spring helps prevent cold leaks. This is according to web research I did in the past.
I used Gates Green Stripe hose to do the job. In my personal experience of doing the job once, in order for Gates Green Stripe to be a practical choice you should be prepared to fully remove and reinstall the metal coolant pipe that runs from the top of the block down to the PHH. Doing this requires patience, agility, patience, long arms, and patience. If you are in short supply of any of the above, I believe silicone hose is the better choice as I understand it can be more easily installed without removing the pipe.
If you use silicone, use some type of clamp that keeps constant tension as rich mentioned. I didn't, and have had problems with cold coolant leaks using napa green silicone and regular lined clamps.
My boat diesel mechanic told me he no longer uses silicone hoses. He said they often drip when cold. You might not notice the small amount of initial seepage on a vehicle, but it accumulates under the engine in a boat. Also, there's many more connections to leak on a boat engine - with all the coolers and heat exchangers.
Don't mean to rain (or leak) on anyone's silicone PHH parade, just passing on the experience of someone who has to live with the results on a daily basis.
When mine was replaced it would leak an amount the size of a quarter if it set for 2+ days. If it did not set for over 2 days there was no leak. Pressure tested it and could not get it to leak. Finally installed some Barr's and it quit leaking. Barr's is also suppose to be good for my water pump and they use it in all new GM vehicles on the assembly line so I figured what the heck. That was 9 months ago and no leaks or problems.