Here is the first major thing about them: researching new vehicles.

In WT(War Thunder), the first German bomber, the Do-17 E-1, it costs 4k RP(research points). I was able to achieve this in about 4 matches at around 1k RP per battle with no boosters(in WT you can get RP and money boosters from 10% to 500%). That took me around an hour to do, the battles being around 15 minutes long. I had great fun doing it as I had three types of He-51's and a CR-42 with very flammable rounds.

As for WoT, when I wanted to get off the first tier 1 vehicle, it took me multiple days for three reasons:
1. Loads of noobs were shooting at friendlies.
2. To advance onto a new vehicle, first you must research 1(or more) mods(modules) for the tank. These were hard to research since I got very little RP from battles from either wolf packs or blue on blue(friendly fire). Once I got the first one, I could barely afford it as money was very hard to get too.

Conclusion: It is easier to get new units in WT than WoT.

I have played each game for about a year now. I only managed to get to tier 4 or 5 in WoT, mainly the LT and SPA. I was progressing in all branches but I wasn't doing that well or enjoying myself.

On the other hand, for WT, I have two accounts. In one(my big one) I am on tiers 2-3 for planes of all countries(5) and tier 2 for tanks on all countries(3). I think that sums up to about 50 vehicles or more. As for the other account, I am halfway through tier 1 on both tanks and planes for Germany, with about 15 vehicles in total. Nearly tier two for tanks and I could be on 2 for planes if I wanted.

It is, just better. Anyone who has played WOWP and WT says WOWP is awful(I think that is just generally accepted) while WT is great. WT has three different types of games: Arcade, Realistic and Simulator. In arcade, everything is done for you(more or less) and it just focuses on pointing and shooting. The main thing is that in arcade, you have a hit marker that shows if the shell penetrates and predicts shell drop, stuff accelerates quicker and skids more and you can only respawn once per vehicle(only three times for tanks). This game mode is specific for tanks only or planes only.

For realistic, the hit marker is just that, a normal hit marker. It does nothing for you. Stuff accelerates normally(I think) and stuff skids way less. You can still only respawn once per vehicle but you can use every vehicle you have(in your squad, anyway) as long as you get enough points for killing, taking hits and surviving in general. Flying targets are not lead and maps are much bigger. If a plane runs out of ammo, it has to go back to it's strip to land, reload and take off. Planes can now only spawn on strips(rather than in the air or on a strip). In this game mode, tanks and planes play together.

For simulator, everything is normal. Tanks rarely skid and can get bogged down in mud(in some maps, anyway). Tanks now go faster on roads rather than offroad. Tanks are no longer displayed as friendly, you have to find out yourself(they are divided into teams of Axis(Germany) and Allies(Soviet and America). If you accidentally(or purposely) kill a friendly vehicle you are immediately kicked from that round. Once you pick a vehicle to play in, you can use this vehicle twice(more if you have backups I think) and only this vehicle. You are pitted against realistic enemy's rather than a Bt-5(if you decide to take it into a tier 3 battle) versus a Tiger.

I think I got the biggest things. Realistic and sim battles give more RP and money than arcade.

Lol, yes that is what tank development does. The KV-1 can be killed though. I was flanking on a ridge because about 7 of my guys were swamping a KV-1 when one guy in a Pz. III went behind it and one shot it up the tuckus.

Lol, yeah. The get tracked so easy though. When I first got mine, my frontal armour could not be broken but my gun could not penetrate the enemy either so they would just track me and break my gun.