Some of us have or will have a slow and/or intermittant internet connection, dialup or reduced fast connection. The reasons are many: dialup is all some can afford, dialup is all there is in the county side, the fast server is nearly overloaded, storms have damaged the lines or reduced bandwidth, clouds obstruct the dish, your research PC is somewhere in Outer Mongolia and the signal is “VERY POOR”… You get the idea. 
Avast (and everyone else for the matter) isn’t considering that this can cripple computer protection by slowing or stopping important updates. When I had a fast connection, the typical initial definitions update at install was 30-40 MB and only a minute to do. If I had to wait the typical 3-6 minutes per MB on dialup, it wouldn’t happen. The past 2 months, Avast has failed to complete a dialup update to the Dec 2, 2012 virus defs. The program says it wants an update as well. None of the updates indicate how big they are, so I have no idea how long to wait. The update “progress bar” seems no to move at all after an hour. What’s a po’boy to to?
I recommend that the update software be capible of understanding the limits of the connection it’s using. With this info, the Avast servers break the updates into manageable, read UNDER Two Megabyte, chunks that can be reasembled when the update has been completed. Perhaps virus defs could be usable in these smaller chunks… which are close to the daily update size anyway. Or just keep them in the daily size they originally were and solve the whole thing. 8)
Lastly, let us know how big a download the part(s) comming in will be, like a typical file download does anywhere else on the net. That way I can go make coffee or a pot roast. 