Smith Machine Vs Power rack,

[galaxy xr8]

Hi guy's, I am after the expertise off some fellow power lifters around here, I am looking at upgrading to a smith machine, but I'm also leaning towards getting a power rack instead because it is a true free weight exercise machine where as the smith machine still controls some of the movement but as I am training on my own at home, I need the security off the smtih machine as a spotter, my question is, has anybody used a smith machine for strengh/size and gained good results from it, or do you reconmend getting a power rack and controling the movement, I have come across a good smith machine that is built good and I like but I am unsure off which way to go, power rack or smith machine???.