Under very specific conditions, this is the best vacuum cleaner that someone can buy, even compared to models that cost hundreds of euros.
The criteria and ratings related to the above are as follows:
1) Ease of use: 10/10
2) Quiet operation: 9/10
3) Dust retention: 10/10
4) Easy cleaning: 10/10
5) Build quality: 9/10
6) Durability: 10/10
7) Low purchase cost: 10/10
8) Low operating cost: 10/10
9) Transparency of the bin: 10/10
10) Universal type accessories: 10/10
With the exception of this specific vacuum cleaner, there is no other vacuum cleaner on our planet with an average rating above 8.
The three conditions for the above to be true are as follows:
1) The vacuum cleaner must operate with universal type accessories **1 and not with its own.
Specifically:
A) Nozzle with a slot for 32mm hoses.
B) 32mm diameter hose.
C) "G" handle compatible with the rest.
D) Spiral hose.
**1 We can obtain accessories of this type new from any store, and any manufacturer - brand, at a very low price (25€ for all) or use the accessories of an old vacuum cleaner as they have a lifespan of 10 to 100 years.
2) We need to improvise regarding the adapter that connects the spiral hose to the vacuum cleaner, for which a 10cm long, 32mm diameter pipe is sufficient, preferably made of PVC, which we will wrap with duct tape on both ends to fit tightly and with sealing.
3) The filter is not easily found as a spare part, so:
A) We never wash it.
B) We always use an extra filter **2.
C) We clean it by lightly tapping the black "lid" with the handle of a wooden or plastic brush.
D) We never tap the filter on the white surface or the large side that fits into the bin! !
E) We clean the filter peripherally with a brush on the black surface, not on the white surface!
F) For cleaning all other parts, we use a brush and if desired, we change and wash the extra filter **2.
G) We never let the bin fill up halfway. We empty the bin and clean the filters as soon as it is filled to 1/4 or 1/3. This is sufficient for a house of 50 to 100 square meters, depending on its cleanliness, thus protecting the filter from any high pressures due to the collected dirt.
**2 As an extra filter, it is suggested to buy a 100% synthetic women's sock, costing around 1€, which will "produce" at least 4 filters with a lifespan of about one year each.
The above technique extends the lifespan of the vacuum cleaner from 2 years to 10 years (read the end). With the same technique, the filter is cleaned up to 10 times easier, faster, and more effectively.
After a technical analysis, we can say that the motor is a jewel of design, performance, and technology that is hard to find better. The rest of the vacuum cleaner's design could be better, making it even quieter up to three times, but slightly increasing the volume, weight, and certainly the cost. However, do not be deceived by the above comment, the vacuum cleaner is extremely quiet.
End: just like everything around us is designed and manufactured with weaknesses in order to be destroyed so that we buy new ones, this vacuum cleaner also has its "weak point", which is its filter. If used as is without the aforementioned tactic, it renders the vacuum useless after approximately 100 to 150 hours of operation, which translates to a period of 2 to 2.5 years, meaning the end of the warranty. The calculation was based on using it for 10 minutes per day or 60 hours per year.
Numbering of the three photos:
1) The complete vacuum cleaner.
2) Components with a total cost of 25€.
3) Extra filter that needs to be applied.
4) Origin of the extra filter.
5) The extra filter was properly placed in the bin.
6) Adapter between the hose and the bin.
7) This side requires 1 extra wrapping.
8) The adapter.
Purchase price: 24.90€
Update 19/3/23: Two years ago, the filter was very expensive and only available from German websites. At the moment, the filter is available everywhere for a price of 3.50€. This adds value to the vacuum cleaner, but it does not change the tactic in terms of usage. I will immediately purchase the filter and post an evaluation on its page as soon as possible, covering its origin-authenticity, application in the bin, pollutant retention capacity, construction quality, compared to the filter that the vacuum originally had. I found the filter on Skroutz by using the keyword "deerma dx115".