Also, the price comparison is somewhat apples to oranges, as the Lenovo is refurbished whereas the Acer is not.
Is it considered a good or bad thing that something has been refurbished?
Well, in case you don't know what refurbished means, it's when an item has been previously bought and returned, and is know being re-sold. It's sort of half way between buying new and buying used. It's not a good thing, but I don't know if I'd go so far as to say it's a bad thing either. The main difference is that a refurbished item will often have reduced warranty. For instance, according to their respective Newegg pages, the Acer has a 1 year warranty while the Lenovo has 90 days. Refurbished units are priced lower to reflect this fact.
Am I correct in presuming that a 940M card is better than either 820M or 840M?
That laptop looks good, the best that has been posted in this thread so far I'd say. And you're right about the graphics card. For a graphics card model of XY0, X represents which series it's from. The 9xx series is the latest from Nvidia. The Y represents it's ranking within the series. For both numbers, higher is better. So in this case it's easy to see that the 940M is the superior card. However, it becomes a little trickier when one card is an older generation, but higher ranking, e.g. if you were comparing an 840M vs a 930M.
Refurbished = someone had it and gave it back and now they are selling it again. Usually, there's a reason *why* they gave it back and usually it's something minor, but annoying (dead pixel, bent chassis...)
Am I correct in presuming that a 940M card is better than either 820M or 840M?
Usually, the higher # the better, but not necessarily.
Comparison (3D Mark 06 benchmark points - the higher the better) AMD Radeon R9 M275 - 10378 (Lenovo Y40-80) nVidia GF GT 940M - (no number yet, but positioned a little higher on the ladder than 840) (Asus) nVidia GF GT 840M - 10325 (Acer) nVidia GF GT 820M - 7518 (Refurbished Lenovo) Intel HD 4000 - 4412.5 (Non-gaming computers ... and this seems a bit higher than it should)
Occasionally refurbished models will be one which had a serious fault and the model was replaced while the machine was being fixed. Don't know about USA but in UK unless you are clearly told of an issue with a refurbished machine you can still take it back. The one positive of refurbished is that someone has actually run and tested your machine. With brand new models they only do batch testing which means the first person to find a fault will be you. This may mean you have to take the machine back for repair or replacement
given all of the options listed thus far, I would personally lean towards the Asus. They are one of the most solid manufacturers (Lenovo being second among the choices listed) and for my own personal money, manufacturing quality/integrity is at least as important as blanket stats.
With that being said, I think that any of them will do the job, at least in the short run. You might end up hitting exactly this same issue in a year or two because new hardware is always being worked on and the software is usually written to make use of the advantages if not directly then at least eventually.
Comments
After even further research, I came up with this ASUS model - what do you folks think?
http://www.newegg.com/Product/Product.aspx?Item=N82E16834232376
Intel Core i5 5200U (2.20GHz)
8GB Memory 750GB HDD
NVIDIA GeForce GT 940M
1920 x 1080
Windows 8.1 64-Bit
DL DVD+-RW/CD-RW
Am I correct in presuming that a 940M card is better than either 820M or 840M?
Comparison (3D Mark 06 benchmark points - the higher the better)
AMD Radeon R9 M275 - 10378 (Lenovo Y40-80)
nVidia GF GT 940M - (no number yet, but positioned a little higher on the ladder than 840) (Asus)
nVidia GF GT 840M - 10325 (Acer)
nVidia GF GT 820M - 7518 (Refurbished Lenovo)
Intel HD 4000 - 4412.5 (Non-gaming computers ... and this seems a bit higher than it should)
(source: http://www.notebookcheck.net/Mobile-Graphics-Cards-Benchmark-List.844.0.html)
With that being said, I think that any of them will do the job, at least in the short run. You might end up hitting exactly this same issue in a year or two because new hardware is always being worked on and the software is usually written to make use of the advantages if not directly then at least eventually.