I've used a LOT of mice over the years, and I went wireless way back. Currently I use a Logitech MX Revolution on my main home machine and another on my work notebook when it's docked. For travel, I use a Logitech V470. I'm no hardcore gamer, but the Revolution has always performed very well in every application up to and including casual gaming. The V470 is my second Bluetooth mouse (on my second Bluetooth notebook) and also performs very well.
I use my notebook all day every day at work, so I only get about a week of battery life out of the office Revolution, but it charges fairly quickly and I always have the Bluetooth mouse for backup if the Revolution runs low while I'm working. No manual switching necessary, it just works. The V470 runs on AAs, and I have yet to need a battery change, but I've only had it for a few months.
The one thing that will drive you crazy with some Logitech wireless mice, the MX Revolution among them, is their crappy charger design. I love the mouse, but you have to keep the charging contacts very clean (especially on the mouse, where a small pencil eraser helps) and fiddle with placement in the charging cradle waaaaay more than you should, especially with an older one. It's enough of a problem that I've seriously considered "acquiring" some electrolytic paste (like they use on ECG contacts) to make charging easier. That being said, it's still worth it.
To zero in on your original question - I would avoid USB dongles unless they are tiny enough that you can leave them plugged in all the time. I killed my first notebook (the one before the one before this one) by plugging a USB dongle into it one or more times a day - eventually the USB port separated from the motherboard, and everything went to hell after that. This, incidentally, is why I use a dock at work... and why both of my subsequent notebooks have had Bluetooth and a Bluetooth mouse.
So... I'd say go Bluetooth, and the V470 is a good choice if you're after a compact ambidextrous mouse with good battery life and a power switch (you want a power switch). Good luck!