Will Upgrade Cause Issues?

Hello. I'm currently running Snow Leopard 10.6.8 on a 2010 macbook, with 4GB RAM, 2.4ghz Intel Core 2 Duo - it used to be running fine, got a little sluggish, so I did a clean install a few months back only it's not really speeded up my laptop (in fact, it seems to have slowed down if anything, I'm always getting the spinning colour wheel, plus some applications I used to use I no longer can, presumably because they've upgraded when I re-installed).

So I was wondering if I should upgrade to the Yosemite OSX? I read Mavericks is no longer available and there seems to be a lot of bad talk about Yosemite, and my laptop is just about minimum standards to support it, so is it worth it?... I do mostly browser-heavy stuff (when firefox wants to work without chewing all my RAM), extremely basic photo editing, no video stuff, it's basically just a general "surf the web, watch movies, listen to music" laptop. Thanks for any insight into Yosemite.

I run an older MacBook Pro than yours, a 15" 2.8 GHz core 2 duo mid 2009. It's been upgraded to 8GB, a 512 GB SSD and a 1TB 7200rpm data drive in place of the optical drive. It runs Yosemite without any issues, and Photoshop CS6, Lightroom 1.57, Photomatix, Autopano Giga, Tonality Pro, Office 2011 and Apples apps. My wife uses an older 15" MacBook Pro 2.4 GHz late 2008, upgraded to 8GB and a 250 GB SSD and Yosemite. She just uses Apples apps and Office, and finds it very snappy, a big improvement over her old 2007 MBP 6GB running Mavericks. Theoretically, an old 2007 MBP could run Yosemite, but I wouldn't recommend it. For your use your MBP certainly doesn't have the minimum spec, but a memory upgrade and SSD will make all the difference. We haven't had any issues with Yosemite, but there have been some (not effecting everyone) that weren't fixed by the last upgrade.

Have to agree with Steve on this. I've got the late 2008 version of Steve's machine with the same updates minutes the 1 TB drive. Although Yosemite officially requires 2 GB IIRC, I don't think anyone here would suggest that most of the OS versions from 10.7 on wouldn't benefit from having more than 4 GB of ram.

If you update past 10.6.8 remember to check your software 10.7 and higher will not run Power PC software.

If you did a clean install due to speed issues, and then after a clean install, your machine seems to be just as slow or slower, it's highly probable that your hard drive is on it's last legs and should be replaced. I personally wouldn't upgrade anything with that description until the drive gets replaced