Ease of use (client and technician) vs. cost vs. features
Teamviewer, of course, although free for personal use, seems relatively pricey for it's initial install in getting set up 'for business use'...minimum, $580-ish? However, it works, every time, and, seems to work well, even internationally! (I use it all the time to maintain my mother's PC, from Okinawa, Japan to South Carolina, USA!)
Ammyy---- $66 (up to 4 PCs controlled), or $99 (unlimited), one time expense; tested from a Win7 laptop to an XP virtual box instance, seems as easy to use as Teamviewer, which is saying something!
UltraVNC---free, but, in my testing scenario, I only got it to work once from Win7 to XP virtual, not sure what the issues were just yet;
As for the relatively vast assortment of $300-up yearly/$25-40 monthly's (with perpetual expenses 'forever'....I will evaluate their ease of use vs. cost vs. features, but, from my limited testing, in my opnion, it seems *very* hard to beat Ammyy's ease of use, low cost ($99, once?!), although, it does seem limited to Windows only, but, that hardly seems of concern to me personally. The monthly/yearly crowd would have to offer a pretty extreme set of advantages to justify their costs, especially to a small business...
Eager to hear others' thoughts on these issues...
Cheers!
Mark