Manoeuvrable Trolley with backpack function

I was looking primarily a trolley, with which one a handful of books (for signing) can be transported on a book fair. The backpack function was for it not so important to me, but is very useful for scheduled air travel. I list below the advantages and disadvantages for my purpose to use:

Positives:
+ Easy access to books and records because the front door is not omitted after opening. However, while packing clothes from the restricted orifice is disadvantageous, but perfectly acceptable.
+ Very good free processing of seams and the carrying handle.
+ Even with high load (a lot of weight) by the carrying handle to carry, without being afraid of seam cracks.
+ Laptop compartment well padded.
+ Wheels are on the outside and smooth running.
+ Wheels can be changed. That's not the case even with many brand trolleys.
+ Spacious front compartment for cell phone and other small items or for supplies. Beverage can and flat food container can be accommodated easily.
+ Additional (third) outside zipper for papers, cards etc.
+ Bottle holder on both sides (for bottles up to 0.5l).
+ Backpack straps can be stowed well. Relatively simple attachment of the straps with snap hooks.
+ Good wearing comfort as a backpack.
+ Approved as hand luggage with Lufthansa. In particular, the depth of 20 cm is useful here. Depth-maximum of 23 cm is exceeded by some other products.
+ Stable handle which has some play.

Neutral:
o Zipper Zipper could be made larger. I would like to see as an outdoor jacket.
o color selection limited right. Black looks bored out, the two-tone green tone seemed a bit more modern and would be my recommendation.

Negatives:
- The handle has only one locking point, so that a grip height of 1,13m results. This is for people with a size of 1.75 m high, especially since the trolley with handle pulled then acts quite big. Many other backpack trolleys have appropriate handle heights of 90 to 95cm. For me it would have been almost a reason for return. That reminds me the rest of free processing really liked, I have in the linkage of two additional holes drilled (6mm) so that my trolley is now engage in 95cm and 113cm with. I would like this by default. For a point deduction.
- At the bottom of the trolley a Velcro strip for securing the rear cover with backpack use is attached. The velcro comes in (loaded) Trolley but on the (exhibition) carpeting and can be hooked something there. It can indeed be solved easily, but the velcro contaminated in this way gradually. The ground clearance is therefore slightly too small dimensioned. Become So think about it, cover it with a Velcro future counterpart. For 0.25 points deduction.

So to sum it 3.75 points for this product. If you can live with the weaknesses, for this trolley is well suited.