I bought the PzIV after selling the panther. Will play it for fun and some xp (have around 750 gold left to convert) and keep it. once I get xp for tracks/turret I may rebuy the panther...we shall see. There is still the grind for the 75/100 and I'm not too keen on it.
I feel I should expand on this a bit.
I've been playing video games since I was 13 years old and got my first PC. I've had many single and multiplayer games, and played WoW for nearly 4 years.
WoT is the FIRST game I've played where you are constantly frustrated by the "leveling up" process, forcing you to suffer through ineffective tanks/weapons for quite a while before you get to enjoy anything.
In WoW, leveling up gains you new skills and abilities, opens up new areas to explore and you are feeling your power grow, bit by bit versus mobs around you.
In Diablo 2 you gained new abilities and leveled up your used ones to make them much more powerful, keeping up with the enemies around you.
WoT however, makes you forever-inferior until tier 10, only because there is nothing further up. There is 1 major difference between it and, for example, Battletech that makes it painful. In Btech, your weapons do damage to just about anything - yes, your Wasp will do pitiful damage to an Atlas but you are never "just xp fodder". This makes (and will make MWO) Btech really fun, since you can be useful no matter what you are driving. A newbie in a fresh Commando can scout well and do hit&run as needed/possible while the rest of his team does most of the damage - he is not useless.
In Wot, armor penetration coupled with the MM throwing you against tanks 3-10 years ahead in design vs yours mean you are there to either 1)go against the lower tiers like yours 2)feed higher tiers.
Another problem is the simple fact that lower tiers are mostly tin cans with guns. Only when I got to the T20/M26 I felt like I was in a real tank. Shermans (we have em on display here, several variants) were buckets with guns, fun but limited in usefulness. They are free kills for T8's. So you grind away to get to your favourite tank, always in a chase after that elusive unicorn.
I may decide I'm fine with sticking to lower tiers only - the battlefield is fast paced, a bit more balanced and way more fun.