I've found BF4 to be generally stable and most of the time works OK. There are obviously some bugs in it (as all software has) and compared to launch it is much improved. Like BF3, some of the additional modes and maps soon get forgotten even though some were not too bad. I've wanted to get a few assignments completed but finding active servers with some of the modes and maps is near impossible with vanilla or latest DLC being the most common.
I'll wait for Hardline to go free before I get that because it just doesn't look like value for money to me (especially as I have a new iPhone, iPad and iWatch to get

)
. I'd joined Laka on a server the other day (only to realise a bit later it was BF3 and that was still fun and something I would go back to. Having tried BF2 again recently I felt that was really too old (for me) and I didn't enjoy playing it. I'm glad to see the effort that is going into keeping it alive and hope the players appreciate it but it isn't for me. It is a bit like people who still enjoy vinyl records, I understand why they like it but it isn't for me now - I used to own a Linn LP12 and had over 800 LPS but it was a lot of hassle to use and CDs were pretty good to listen to.