I had difficult time deciding between SEKA and Elilee, as I thought both are good option. I ended up getting an Elilee. I have not been able to ride the Elilee Blize outside yet, since it's still a little cold up in the northern part of the US (I am a fair weather rider).
One thing that might be overlooked is how easy it is to actually purchase the frame. I kid you not, I sent three emails, Instagram DM, FB message to official SEKA accounts and I hear no response. This was me trying to buy the frame directly. Meanwhile, I got prompt response from Elilee and they have been responsive and answer all my questions even before I decided to get the frame.
Yes I also explored the Seka option almost a year ago (between may and july 2023), it was near impossible to get a response. At first a sales person did respond and mentioned they would shortly (within 2 months) offer direct purchase via their website. I am then near pulling the trigger and then no response. Tried them a few more times for about 6 weeks and then gave up