How is it these days? I enjoyed it for a while, but found it a bit too repetitive doing the same quests day in day out, week in week out. When that expansion came out that didn't include a raid and was basically go get the same weapons but at a slightly higher power I was off. Loved Vault of Glass though, that was great fun, the second raid not so much as I could solo the whole thing which kinda takes the fun out of multiplayer.
The taken king expansion basically made all old weapons and armour obsolete, the levels pretty much doubled from 170 to 335 as the max and brought in a new enemy class (the taken). Also added a new playable area called the dreadnaught.
With the latest rise of iron expansion light level has now been raised to 400 but taken king gear can be infused up to that level and another new enemy class (the splicers) and added the plaguelands which is on Earth.
Its pretty much the same old same old but there is the oryx raid and the new wrath of the machine raid too. Also a lot of the strikes have a few different variations now with the taken enemies and the latest splicer enemies so they aren't identical each time you play them. Its always going to have an element of repetition in though. I just enjoy playing it with the group of my friends that I play it with, if I was playing it solo I'd have ditched it a long time ago I think.