help & guidance wanted. I have a macbookpro 4.1 OS SL 10.6.8 Processor Name: Intel Core 2 Duo Processor Speed: 2.4 GHz Number Of Processors: 1 Total Number Of Cores: 2 L2 Cache: 3 MB Memory: 4 GB will an update to yosemite be wise? or other? advise please? I'd primarily want to update so I can use sketch up pro (student version) need higher than 10.7 - otherwise I've survived fine without an update. ps budget conscious options welcomed.