I 100% SA1 last fall and just 100% SA2 a few days ago, playing them both for the first time then.
They're pretty solid games and I enjoyed them a lot coming off of the classic 2D Sonic games. A little janky at times (mostly camera issues getting you killed at times or just being annoying) and with characters that aren't super great to play like Big and the mech stages (to an extent), but still fun overall. The Sonic/Shadow stages were really good in particular.
Think I might prefer 1 over 2, the adventure fields were a nice touch and the spindash and radar nerf in 2 were annoying. It's a close bar though, and I ended spending more time in 2 anyway, though that was cause getting all the A ranks in 2 is a genuine challenge that can be really fucking frustrating. Also, the Steam version of 2 was noticeably more crash-prone compared to 1.
>>16
Yeah, they're pretty popular still in the fandom, many still consider either or both to be the best 3D game in the series.
And I definitely agree about the passion bit, Sonic fans have one of the most active fangame scenes for any franchise. Hell, the SRB2 fangame was so damn good it is what actually got me interested in the series proper.
That said, it's still an annoying fanbase in a lot of ways. So many fans still whinge about the "sonic was never good" meme to the point there's a gorillion sonic youtubers praising the worst games as hidden gems and shit. The sheer amount of them creaming their pants of Sonic's characterization in Black Knight is astounding.