Wikipedia said:Higher cost than aluminum electrolytic capacitors. Voltage limited to about 50 volts. Explodes quite violently when voltage rating, current rating, or slew rates are exceeded, or when a polarized version is subjected to reverse voltage.
Slew rate refers to how quickly a capacitor has to go from charged to discharged state, or vice versa.
It's a fairly dangerous game, to replace them without knowing the hardware intimately, as you may unwillingly set yourself up for future fireworks and I would ask the question, if you're still going to replace the through hole ones with more through hole ones, then you will still have to change them the next time too.
I can't easily get the proper SMD types of tantalums, what I was going to suggest was to cut the legs short and bend them to form a U shape the size of the pad. Only thing with that is, if you accidently strike the capacitor, with an expansion board for instance, then you run the risk of ripping the SMD pads off the board.