I bought this model A515-54-51DJ (received Dec. 20) to future proof my 3-year old Acer Aspire E 15 which has served me very well and still is.  This “Slim” model has an IPS screen, which is an improvement.  It does not have a DVD drive like the old E 15. It also does not have an SD card reader.  My use is only for non-gaming and for very light graphics.Fan Noise: An early review of this “Slim” model criticized the fan noise.  Although I will admit that the fan noise is louder than my old E 15 (which is quite quiet), yet it is not too offensive and usually settles down under normal use after startup or extra hard applications have finished – YMMV.  I doubt that a neighboring table at a coffee shop would notice it at the lower levels. The noise level is about identical to another very similar laptop that I recently purchased (Lenovo S340).SSD: Any computer without an SSD drive today is asking for frustration.  The 256GB SSD seems to be the best value and is just big enough to work with, and then I use attached USB HDDs or USB thumb drives for larger storage and backups, or, of course, online storage.  My 3-year old Acer with SSD is still going strong… and quite fast.  I can’t imagine ever going back to a main drive HDD. – RAM: Upgraded to 20 GB with a 16GB RAM stick from Amazon/Crucial (took 10 days to receive it during holiday season) – it now shows 20GB in Windows System, although the first startup time took nearly 30 seconds to get started, causing no small amount of concern.  But after the first time, now it starts up in maybe 3-5 seconds from Power Off.  20GB seems to be perhaps the most RAM one can get in an economical yet powerful productivity laptop like this.  The ultralights don’t generally come with the ability to upgrade RAM to more than 8GB.  For those who need dozens of browser tabs open, lots of RAM is needed. – Video: I plug a 4K 43” TV into this with an HDMI cable for extensive screen space for my productivity needs  – works well, just like the old E15 did. Standard online videos play well. Again, not for gaming use. – Keyboard/trackpad: Both work OK for me, no problems with typing.  The Function Keys no longer default to the old Windows F1-F12 functions, but you must press the ‘Fn’ key along with these now to get the old functionality.  I.e. to rename a file, one must press ‘Fn + F2’. I did not have any problems with the trackpad, only that I have to keep my wrists away from it or the cursor will jump around on me.  See below for comments on the Number Keypad.Pros: – RAM upgradability – 20GB RAM potential (4GB soldered, 16GB stick on my A515-54-51DJ model) – IPS screen – better viewing from different angles than straight on. This is the disadvantage of the cheaper TN displays. The similarly configured “L” brand laptop sold by a US office supply store is at least $50 cheaper (even more on sale) because of this.  For my part it, was a tough decision to pay the extra money for my productivity (non-gaming, non-video) needs. Still the IPS display is nice to have. – USB ports  – Acer has 1 more port than its main competitor (“L” brand) in this configuration – always handy to have plenty of USB ports.Cons: – No SD card slot – not good if you want to work with a camera using SD storage. One must then purchase an inexpensive USB SD card reader.  The greater problem is that it would take up a USB port, and would be an irritation to have to carry it along with the computer.  Even my Chromebook has an SD card reader. – Number Keypad - the right-most column of keys of “+” (plus) and “-” (minus) have been moved to where the “/” (divide) and “*” (multiply) keys were above the number keys.  The ‘/’ and ‘*’ have moved to the top row replacing the old “PgUp” and ‘PgDn’ keys which are now gone.  The result is that the only way one can go “Page Up”, ‘Page Down’, ‘Home’, or ‘End’ is to turn the Number Keypad off which then activates these alternate functions.  I would imagine anyone wanting to do accounting work or heavy keypad work may want to get a USB number keypad with all the original keys and positions. – Service: Although I have felt Acer support service was at least decent for US customers based on what I read, I now wonder about this and will monitor Amazon reviews on this.  Hopefully I won’t need service for the life of this machine.  (Acer  – are you listening? Don't sacrifice US service -- keep knowledgeable, understandable people on your support staff.) – Value: This is a good value, but there is competition in the marketplace.  Hopefully Acer’s popularity will keep them making good products with *good* service.  -- The next 10th gen Intel i5 processors do not appear to have any large speed increase over this 8th gen to justify their cost increase so maybe this unit will be a workhorse for more than 5 years from now.  As support for Windows 7 goes away, this should be a good long-term replacement for a broad range of users… except high-end game players or heavy graphics users.