"Accuracy" of the heritage population results will depend on the basis data and how that data is grouped. If they don't have good data from Finland, and have grouped Finland inappropriately with other regions, the results will be different from your expectations. This doesn't represent "testing accuracy", but "heritage analysis accuracy", which is an inherently inexact process.
For heritage analysis, I much prefer the admixture utilities at Gedmatch.com to the results I've received directly from testing labs. The admixture projects disclose details about their basis populations, and allow results to be calculated using different groupings. When the labs tests for heritage they give much less information about their process and no options. They infer their basis data is perfectly representative and grouped in the only possible manner.
I might be interesting in using their services, because the price for what this lab seems to offer is amazingly low. However, before testing with this lab I would be need to know:
1) That their raw data results are accurate.
2) That their auDNA results could uploaded to GEDmatch.com
3) How many SNPs (for auDNA, y-DNA, and mtDNA) they analyze and which Autosomal SNPs are excluded.
The company website gives very few details about the actual results they provide. Before I would use this lab, I would want to have their testing metrics, such as those shown in the isogg.org tabulation linked below:
Data analysis can change and be improved over time. The basic quality and quantity of the raw data must be acceptable from the start.