There are plenty of previous ice fishing reel threads on this site that have been active the past two years. Also threads on winterizing reels with cold temperature lubricants and carbon fiber washers. I know because I read and reread many.
Sienna 500 is still made and available … places sell out because they are still popular.
About 3-4 years ago I jumped back into ice fishing (never really left, but other responsibilities kept me off the ice more often than not). I have shared on other threads my plan to upgrade most of my outdoor gear before I retire (still 5 years off I suppose) … anyways …
I have purchased 10 or so smaller ice fishing reels over the past two winters … a 13 brand in-line and the rest are spinning reels (multiple-Sienna 500s, multiple-Okuma Ceymars, Daiawa QR750, AbuGarcia Ice Max, 13, and a Pfluegger (came with a Fenwick rod). I have winterized most reels because over half of my ice fishing is outside of any type of shelter.
I would say that I am not disappointed in any. They all function as expected.
I use my in-line reel paired with a highly sensitive rod the most – crappies and other panfish. People I ice fish with (using my gear) have not had any problems with the reels above.
My Ceymars are on deadstick rods … I am thinking that I may put a Ceymar on a walleye jigging rod to test it out more.