Regarding a better computer, yes it helps . I had a dual core processor at 2.8 ghz, now a quad at 3.8 with hyperthreading (it helps a lot in multitasking letting sketchup to use the most of one core). A model of 10 mb loads under 5 seconds now,then in about 15 ! I had 2gb of memory now 16 but I haven't seen a consume greater than 6 gb (but not from sketchup which uses around 400mb for a 10 mb file). I haven't changed the video card though but I know it helps a lot cause I saw the difference between the integrated video card and a dedicated video card .
Crashes still occur,the overall performance of sketchup seems slightly improved .
What I am glad is that when the program is Not responding it gets worked out after some dozen-s of seconds depending on the operations you were doing . With the old pc when the Not responding message appeared it was almost clear, I have to close it .
Honestly I thought with this performance it should run like rocket and never stop ,but it seems to be a not well grown up adult!
I believe that without the plugins won't crash at all!
I hope it helps a bit,although this is just my second PC(ever); so there might be others who have made many upgrades including video cards and the new SSD storage disks(which I heard are way better than regular HDD's) therefor helping sketchup work and load faster .
Take care !