NO! It's a complete waste of time in our opinion.
Unless of course you're a big fan of spending 8-12x the cost of sea freight whilst saving only 4-5 days?
The China train service offers a fantastic alternative for cargo travelling from Yiwu to Eastern Europe, where the cost sits somewhere between Airfreight and Seafreight, with a transit time of around 50% less. However, most suppliers will be offering FOB terms from a nearest seaport and not Yiwu, so firstly you have to consider the additional costs for taking your container from most likely a coastal city, nearby to the port vs Yiwu terminal. If you're lucky and your supplier offers FOB Yiwu, then we can move to the next question.
How long does the train take? From Eastern Europe which takes around 12 days, the train then travels through North Europe to Hamburg, tranships to another service and calls to London eventually, some total of around 18 days. Seafreight from Shenzhen is as quick as 24 days, so saving just under a week doesn't seem so appealing for the extra expense of 8-12x as much cost, especially when a similar cost depending on the total size could get you Airfreight within 4-6 days.
The train service has a maximum capacity of containers it can take, and therefore it's operating cost is always going to be stable. If you bear in mind that the largest of todays sea vessels can take up to 22,000 containers, the cost proportioned per container is always going to win this comparison.
This is why, sea freight will always be the most cost effective method to import your products, and if it's a deadline you must hit then Air freight is the most sensible option.