The X-Man Spark was first released all the way back in 2019 and was the best 7x7 for a while, it was what got me into 7x7 speedsolving and one of the cubes that allowed me to drastically decrease my times relatively quickly, I used it to come 2nd in the UK championships 2019, however, other cube brands have since made better 7x7s and the Spark isn't used much anymore. QiYi have now released a successor which aims to be competitive with modern 7x7s, it is the first mass produced 7x7 to have a ball core and is available for only £32 which means it is actually cheaper than a stock AoFu WRM. It is a bit slow right now although I can maybe speed it up a bit but overall I think it is a worthy competitor and it will be interesting to see if top 7x7 solvers start using it (unfortunately I can no longer consider myself one of them).

You can buy it here.