I've had really good luck with gear from raid kills. I got an ascended dagger this week, and a Ghostly Infusion the first time I killed Gors. So now my list of ascended weapons has grown to the point where I'm making weapons before I have alts that can use them.
On the armor front, it doesn't seem like I'm using my tempest as a dps very much, so I've started using my shards to buy Yassith's gear for my necro. Gearing a condi class is very difficult compared to gearing a power dps, so I've decided to do most of that via shards. After I finish off my mesmer, I'm going to take a break from levelling and trying to gear out alts to make sure that my characters are in order. I'll have the following classes:
I've been having fun helping guildies gear and advising them on what to level, but the bottom line is this: if you want to raid and you don't hate on a primal level the heavy armor classes, you should craft an ascended heavy armor set and a few weapons that you can share among them. Warriors, revenants, and guardians are in demand these days in raids, are good 'alt' classes in that you can do average raid dps/performance with them without too much trouble, and don't have any gearing quirks that prevent you from sharing armor.
To the above list, I hope to add warrior and condi engineer eventually. The only reason I'm finishing out my mesmer and then taking a 'break' is because he's level 63, whereas my warrior is only 14. Even though levelling isn't difficult in Guild Wars--and I enjoy it--I'd like to feel a bit less pressure to have everything immediately, and I like to do at least some in-world levelling, which can be tiring.
Also, I've spent about 90% of my raiding time being a guardian, 8% being a tempest healer, and 2% being a tempest dps or condi necro, so you could argue that I don't *need* other alts except from a raid convenience/composition standpoint.