The fixed/floating decision isn't as simple as it first appears. Security is a factor for fixing rates, yes, but not the only one.
Financial people will say buy low, sell high, and likewise fix rates when they are "low", whatever that means
to you. However the first thing to analyze is the gap between floating and fixed (5 or 10 year) rates. Historically this gap has been more than it is now, and its unusual to have both (a) rates at the low end of the curve, and (b) a narrow spread.
So consider what you think will change. Historically, and even more so with rates at current levels, the first thing that happens when "rates" rise is long term rates start to rise and floating rates don't. And because that "happens" and most everybody finds out after the fact, you then have a choice. Lock in at a rate more expensive than you could have obtained last week/month, or "stick it out" and "watch it carefully", vowing to make the right move..... If you catch my drift.