Sl2 improved in low light high iso over sl1?

I owned an SL1 and now have an 80D and a fuji x100 so I thought I would join the conversation - even though I am a couple of weeks late.

I basically learned digital photography on an SL1 (now sold). I really liked it for its relatively simple interface, great touchscreen, compact size and, of course low cost. I have an 80D now (and a 6D) but often wish the 80D was an SL2.   The 80D has the same sensor as the SL2, but it is heavier/ bigger and more complex than the SL2.   Unfortunately, it just isn’t practical to swap the 80D for an SL2 because the 80D has several capabilities the SL2 does not have - such as a more sophisticated focusing system, better flash controls, anti flicker and the ability to focus long lenses with a maximum aperture of ff8.

One disappointing thing about the SL1/2 cameras is that as the OP mentioned, there is the complete lack of a 28mm prime in the EFS lens line up.  From what I just read above, Nikon DX shares the same problem.  That is the main reason I recently got the Sigma 17-50 f2.8 for use at low light events. I have only used it for one event so far. I can say that it has a very convenient zoom range and the constant max aperture of f2.8 is helpful. But I need to use it more to really get comfortabke with IQ performance. What is clear though, is that an 80D with an f2.8 zoom is no lightweight stealth camera.

So for travelling light and shooting silently I bought a fuji x100 last year. It was introduced in 2011 so it predates the SL1.  I really enjoy using the camera but high ISO shooting is not one of its strengths - it might be about the same as the SL1 or possibly worse. The poor EVF also takes away one of the strengths (IMO) of mirrorless,  which is image review immediately  after capture in the EVF.  The image is presented pretty quickly but it is hard to see well and has low resolution.  The x100 does produce great JPEGs and has a very good 23mm lens.

Today I visited my local camera store to talk about printers and I found out by chance that they had a used fuji x100S on the shelf. So I had to take a look,  naturally.   It looks like a great upgrade from the x100 original.  I am going to hold off going back until Monday to see how much they would give for my limited edition black x100 in partial trade.  I am really hoping the updated body will produce acceptable images at ISO 6400.

So I certainly would not discourage OP from owning a x100s or x100T but I am still fond of the SL1/SL2 line of compact DSLRs.