Obviously you get the room you want, in the location you want, when you book a specific room. If you go with a guaranty you may end up in a less desirable room but then you also have the chance of getting an upgrade. Also, sometimes guaranteed rooms will be discounted, but not always.
We've thought about guarantees several times, but we invariably decided in favor of known cabin assignments. I figure when I pay beaucoup bucks for a cruise, I don't want any big surprises. Like Harry said, you might get a real good deal or you might end up in an unfavorable location. I suppose a lot of it depends on how full the ship is, like most good/bad options. We'd just rather choose exactly where our cabin will be well prior to our making final payment.
Guarentee cabin's aren't generally the best idea if you are: picky about the cabin location, prone to motionsickness, or a light sleeper. Since we are none of the above we go with the guarentee to increase our chances of getting upgraded. So far it has worked well for us, we have been upgraded each time. And it is usually a little cheaper for us to book that way.
Moon, a cabin toward the bow of the ship tends to have a bit more movement, you will be able to hear the anchor chains being raised and lowered. You probably will have to walk further to get to the elevators and such (don't know the lay-out of the ship)
Walk! Walking is good for you( unless you have an actual disability).
We book guarnatees, we like to save money, and we booked an inside and got upgraded to a balcony on the Grand, lucky we know, but we also know we paid a rock bottom price for a great cabin. The truth is you have to have the attitude that you don't care what cabin you get, and then where ever you end up is good.
We booked a balcony guarnatee this time as we were spoiled by having the balcony last time, we don't care about front or back of ship, we had the very front before and loved it anyways. It would be nice to book one of the aft balcony cabins as I understand they have bigger balconies but we don't have the dough, so it doesn't bother us at all where we end up. We don't care how close we are to stairs or elevators, we figure we eat like pigs for 7 days we need the excersize.
It comes down to how particular you are about location, I realize that some people care about that, we know we don't , we'd rather save money and hopefully have a surprise upgrade( we know you can't count on them!)
Any cruise is better than staying at home and doing the laundry!!!