Arguably, K27 is just as big boat anchor as K26. It's just bigger. Depending on how much boost you want to run, K26 might or might not be a good choice.
It's a smaller turbo which will give you boost eralier on but it will also run out of steam earlier. I recon you should be able to take it up to around 250hp before it starts blowing hot air.
Thank you for your time,