I think White Van Driver covered the main points. Just to add, on SH it's a 6 day reserve not 14 (which means it's possible to be assigned 2 in a month - rare, but it has happened). One of the main gripes is the seniority gradient for roster bidding on short haul. Maybe it's a bit more equitable on your LH fleet, but people at the top of P32 are writing their rosters, and anyone >40% seniority can guarantee pretty much every weekend off. The flip side is if you're <40%, you'll get pretty much no weekends off - the divide (at least going by ibid) is that sharp. Given most people originally bid SH for lifestyle reasons (ability to be home, no jetlag etc) it's a real issue. It's am issue no-one seems to want to try and solve, when I raised it with the union I was (to paraphrase) told "it's always been like this for junior pilots, what do you expect".
Can't say for all fleets but SH is not a nice place to be right now.