Been using a Logitech cordless for years and cane easily say it's the best mouse I have ever had (and I've messed around with 'puters since before you needed a mouse). It's a rechargeable rather than having batteries that I change - I had a similar one at work which had exchangeable batteries and it didn't work nearly so well and in the end I went back to a corded one.
When my original - and by then long-discontinued - Logitech wireless started playing up I scoured ebay and managed to find a factory refurbished example of the same model which I still use today. When I looked in the shops for current models there was nothing to match it ergonomically.
I can't really comment about the software - it's installed with all 'phone home' and the like options switched off. It adds a little functionality that the native drivers do not but I could happily live without it - it doesn't seem to bundle any disadvantages.