I started playing WoT 1-1-2016, so I've only been playing roughly 2 months. I've had some spare time lately and have been enjoying the game a great deal, so I've managed to clock 2K battles in 2 months.
In that time, I've had to deal with ARTY on the lower levels. My highest tier is the American Heavy line @ T8 w/ the T32 Heavy, so I still see T10s, but not always. I have also been playing the Mutz and KR a great deal, while they are up for rent to train crew and generate credits (I did buy the KR though).
In my time, I've grown to really hate ARTY. Not because of posts, but because of my experience with ARTY in game. I have only played maybe 5-10 battles using ARTY, but I have faced it most games. Even at the lower tiers, ARTY can 1-shot a lot of tanks and for me, that's the crux of the problem.
If ARTY did damage like a Heavy, it would allow the dynamic gameplay that WG is striving for. Anyone targeted has a chance to address incoming fire (ie. move), just like they do vs. other tanks. If ARTY damaged people like Heavies and they have a chance to react, I think people would be less hateful of ARTY.
Remember, this is a game that requires lots of learning and practice to get good at. When all of that time/energy is wiped away by a FUCKING METEOR 1-shotting you, with no chance to know it's coming, no chance to respond and no chance to learn anything other than, "well, I guess ARTY can target this spot on this map", it becomes the shitfest that it is now.
What I propose to fix it:
Dmg output like a Heavy. ARTY can't 1 shot people, but when they do hit someone, that person now knows they need to move, or the next couple of inbound shots will end them. Multiple ARTY can still gangbang a tank, but so can 3 enemy tanks.
Shorten aim/reload times by 25-40%. This allows ARTY to capitalize on targets they are hitting, if they don't get the hint to move, but doesn't give them rapid fire. They need to be paced a bit, since they are firing from the safety of being half of a map away.
Remove some of the RNG from ARTY. Allow better aiming for ARTY players. This will allow Close Support w/ ARTY, as well as, make it something players can affect with practice/skill much more than the current meta of "Aim in front of them, so when RNGesus shits on your shot, you may still hit".
Remove shotgunning. ARTY needs to be extremely vulnerable if enemies get to them. This encourages the ARTY to work with their team more, since if something gets through, they're screwed. They will be screwed sometimes, anyway, but this is balanced by the fact they are shooting from complete safety, for at least, the 1st half of the game.
I profess no expertise other than playing a couple thousand battles and lots of reading/watching videos. This is just my opinion.