So, I was bored, and I decided to tally up all the rewards you get for the "Improved" Battle Pass, mostly to calculate if its worth buying. Here's what you get, on top of the other rewards:
- 19 Premium days
- 4 Million Credits
- 15 exp boosters (+100%)
- 15 credit boosters (+50%)
- 318 universal fragments
- 50 Soviet fragments
- 50 British fragments
- 4 rank II Soviet training books
- 4 rank II British training books
- 2 personal training books
- Bounty Rammer
- 2 crew skins
- Both 3D styles
In terms of Gold cost, I would say it was worth it. 19 premium days are a bit short, with 30 days only costing 2500, but the 4 million credits would put you back 10K Gold unless it was a special. Additionally, the doubling of the number of fragments you can get is good too, which would leave you with 636 universal fragments, and 100 of each of the nations. I would say that alone makes it worth it, since even if you have all the Soviet and British vehicles, the universal fragments can be used elsewhere. The training books are fairly good too, as they grant more than the ones on the standard rewards, and you get the personal ones which aren't tied to a specific nation.
Overall, I'd say its only worth it, if you play quite regularly, and have a variety of vehicles. The points seem easy enough to get, especially since you get them even on a loss. But the fact it is effectively a grind to get all the rewards means that for someone who only plays the games on an irregular basis would loose out as you need a total of 2250 points, which is the equivalent of coming in the top 10 by exp for 750 battles. That is a worse-case scenario, but it shows how much time you have to give to do it. On average, that would be 8.3 battles a day, considering you played standard battles every day for the whole period (90 days), and not including frontlines which runs concurrently to this. However, to get all the fragments, you only need 1850 points, which is an average of just under 7 battles a day of the worst case scenario.
The advantage of the pass is you can buy it whenever in the event and you get all the rewards up to the stage you have achieved upon purchase, so if you find you're doing well, you can buy it then and get all previous rewards, which at 6000 gold is less than than any tier VIII premium tank. So if you have Gold still lying around from Christmas, its something to use it on I suppose.
TLDR: Worth it, if you have the time to earn all the rewards, or at least all the fragments available.
Source: https://www.reddit.com/r/WorldofTanks/comments/fhh12l/analysis_is_the_battle_pass_6k_gold_worth_it/