You were told wrong. You can upgrade to Mountain Lion from Snow Leopard. Any applications that are not compatible with Lion won't be compatible with ML either. The issue is they dropped Rosetta support in Lion so some old PPC apps need upgrading or elimination.
Here's an applications compatibility table. I can't vouch for it's accuracy.
You also might want to do some research about iCloud to see if you want/need anything there; you can access iCloud email via your browser with Snow leopard, but you cannot use the other features. Also, bear in mind that iCloud is not an online storage per se - it is a service to "push" and sync your music and some other apps from one Mac to iDevices. Here is some basic info on iCloud:
And here is a compatility checklist you can use to check your applications:
What specific version of Office do you have? If it's 2008 or 2011, those will run on Lion and Mountain Lion. I would advise to save your money and wait for Mountain Lion since you'll just be spending another $20. As for bad reviews, I've read several about Lion, but I've read far more positive reviews than bad ones. I think Lion really annoyed a lot of long time Mac users because of the changes that were brought in. A lot of the interface changes can be adjusted through preferences such as the hidden hard drive in the Finder sidebar, "natural" scrolling, etc. You can either use Launch Pad or not. There's no problem there. Learning how to use your computer, and learning its features goes a long way toward solving problems. You should always fully explore a new computer and a new OS because if you don't, you'll miss a lot of the features that could have been helpful to you. I suggest that you spend some time at the Apple Store and get to know Lion before upgrading to either Lion or Mountain Lion. You should always trust your own impressions above everyone else's. Too many people that I know don't upgrade because their "computer guy" told them not to. Who knows what beef the "computer guy" has that is causing him to tell you to avoid upgrading?
The only reason I would not upgrade now is that
10.8 Mountain Lion is almost here. Wait a few
months for the dust to settle and update when
10.8.1 is released or live on the bleeding edge
and update when Mountain Lion comes out.
If all your apps and hardware drivers are current,
the upgrade should be relatively painless.
If you still have a death grip on PPC apps or hardware
that only have PPC drivers, then you should never ever
upgrade again and start stocking up on computers that
can still run Snow Leoaprd.
If you are unable or unwilling to upgrade your Microsoft Office, you can install Snow Leopard (and Rosetta) into Parallels 7 in Lion and continue working with your version:
[Click on image to enlarge]
Full Snow Leopard installation instructions here:
For example, I find that some of my legacy Excel 2004 charts do not translate well in Excel 2011 and consequently, I access them with Excel 2004 as above...