Would say if you happen to be in the area of a Tournament then Guarenteed Prize Pool does not matter so much,
But when travelleing East to west Coast or like in My case 6000 miles from UK, Think you would be crazy to do so without a Guaranteed Prize Pool, A look at the recent Laughlin event is a typical example,
People who may have travelled East to west to find only twenty something players and a tiny prize pool must have been livid after being told hundreds would attend, If i would have flown from UK for a prize pool that turned out would not have even covered my air well lets not go down that street!
If you look at the last 2 events i have attended the Ventian and Barona they both seem to have got the right idea with Guaranteed $100k prize pools, This attracts people as A. they are guranteed certain level of prizes and B. they think there may be an overlay created by this, So in fact both cases there ended up with much bigger prize pools then the guranteed one as both had good turn outs.
This to me seems to be the most important aspect on putting on a sucessful tournament regardless of format. People who say $150 or $300 or $1000 entries are to much and puts people off, I don't really agree with there are different levels of players who are always ready to put money in if the chemistry is right.