Toyota Repair: Transmission Fluid Change: shop vs. amateur, changing transmission fluid, rapid oil change

Question
I have a 1995 Toyota 4-Runner, and the transmission fluid has been changed twice in 150,000 miles, both times by a shop.  This time, I am thinking about replacing the fluid myself.

Rapid oil change shops (e.g. Valvoline, JiffyLube, and that genre of service) advocate hooking up a vacuum / pump to clear all the fluid out of the transmission, then replacing it with fresh fluid.

What are the advantages of this approach, and does an amateur "drain and fill" suffice?  

Also, is there a screen and/or filter inside the pan that needs to be replaced, requiring that the pan be removed?  Once the pan is removed, is there a pan seal that needs to be replaced?

Thanks in advance for your time and advice,

Jay

Answer
Two changes of the ATF in 150K miles is not enough, the fluid should be changed every 30,000 miles, if the fluid is discolored and dark looking I would advise having a transmission flush machine hooked up to exchange all of the fluid, not changing transmission fluid at regular intervals is an invitation to complete transmission failure. There is no transmision filter, toyota uses a pickup screen which needs no replacement and if it gets clogged up with metal or clutch material it is usually too late anyway and the transmission has some major problems.