Lately, the Roku has restarted on its own and recently I've restarted it due to another app issue. In each case, it has taken 5+ minutes to complete the restart which was something I had not seen before. I've had it for a few years does this suggest it's starting to fail?

Very possible it's getting ready to keel over. The Roku 3 4200 was first released in March 2013, than a second version (same name, model 4230) was released in April 2015. Even if you haven't had it that long, that's how old the design is. The Roku 3, especially the second version, was one of the best players they ever made, but electronic devices can fail with age. If you still need a wired network connection, the Ultra is the only current player that has it. Most of the larger Roku TVs also have wired. If you are OK with wireless, the Premiere + (3921) is the closest match to your Roku 3, but far more capable. It includes 4K/HDR support, as well as MPEG-2 video support and much more powerful. 

My Roku 3 takes a long time to boot lately too, i know the sd card has caused problems in the past, but i haven't checked if that's the cause this time, so if you have an sd card it might be worth removing it and seeing if boot time returns to normal, if not then yeah, probably just eol like atc98092 mentioned.

Thanks for those replies. Mine is the 4230 purchased new in 2017. I nearly purchased the Premiere yesterday. I'm finding I prefer the way the apps perform on the Roku vs our new Samsung TV. Plus Samsung's support leaves a bit to be desired.

I'm one of those having the login problem with Pandora right now otherwise I would be using it on the Roku.

I do have an SD card in it but now I think I'm just looking for an excuse to buy the new one.

Thanks

Jim

Try a factory reset.. it'll wipe the slate clean.. if after you re-add your channels it's still sluggish, then I'd replace it.

I'm with you about the Samsung apps. I stopped using them years ago.