I have/had both scopes.
The TSA120 is a very fine piece of kit with great colour and tight stars with a properly adjusted flattener. I decided to get out of imaging and sold all my kit. It had very stable focus even in temperature change and required very little fiddling.
Fast forward 3 years after a break and the imaging bug has bitten again. I tried to get a secondhand TSA120 until a local FLT 132 came along. The FLT is a great scope and star tests very well both sides of focus although as an early model it has an aluminium lens cell (I am led to believe) that is very susceptible to temp change and I need to change focus over an imaging session a lot. Later model units have a steel cell that is more stable.
I am about to change to the same filters I used on the TSA120 with the same camera so I could give you an idea of how they perform (if the weather ever lets me). At this stage I am happy enough with the FLT, it's just a bit more fiddly to set up and get good images out of although the potential is there.
Oh..and the TSA120 is very light for its size, the FLT is a beast.
Try here for photos, not a lot of FLT ones at this stage though.
http://www.pbase.com/grahammeyer/astro_photography