default settings, emsisoft is obviously better than avast. Better signatures, better behavior blocker, better scanning speed. Better for users who don't like tweaking
EAM is worse than avast in: web filter (please don't tell me we can add ABC filters), false positive rate
however, with some combination and tweaks, avast may have an upper hand and potentially more difficult to bypass than emsisoft because there are not many things to tweak in emsisoft
for example, avast with hardened mode agressive + smartscreen + disabled windows script host, powershell, java. It's really not easy to bypass. With emsisoft not many options you can tweak to strengthen the protection so it might be a little bit easier to get infected
I'm comparing Avast free and emsisoft AM (paid)
emsisoft consumes a lot of RAM. even with memory optimization, it pushes the memory usage to pagefile/virtual memory, which makes the system swap more between physical and virtual memory in HDD => may slow down the PC. Using more memory is only good if your PC has 6-8Gb of RAM at least. Having 4Gb or less might be a pain and perhaps, shorter HDD/SSD lifespan
avast has very friendly in RAM usage with very small physical or virtual memory usage but this of course will slow down the scanning speed
What is the significance here? I have 8Gb of RAM on my laptop. I was playing fifa 17, 18. My laptop had to work extra hard to swap memory to pagefile causing high disk usage with emsisoft while with avast, it was just enough not to swap anything
therefore, using more memory is not always better, that's my answer if you send me the article on emsisoft website
in conclusion, both are very but you can save your money if you use avast free and learn of to tweak it and combine it with other tools, such as voodooshield, anti-executables, SRP,...