How did you know that it is the blade really for you? I have tried different blades and don't know how it is if it is the one already to stick for a long time. Help me please.
Good question. There are few approaches which you can consider -
1. Try before you buy - most recommended approach and hence no.1 in the list. You can try your friend's paddle and play with it to check if you like it. For me, I honestly like everything initially as this is a just my mind playing tricks on me. But please do try.
2. If option 1 above is not available, then search for forums where you can get what you want at a discounted price. I often do that at mytabletennis.net. Good place to buy or trade TT stuff.
3. Buy it new - this is where you decide to take the plunge no matter what. So, you are sucked in by the marketing and you think this is the one which you should be playing with? Sure, buy it. But - don't change everything at once. Use the same rubbers like the one before. If you have a stronger side and a weaker side for example, strong forehand and weak backhand then first change to a new rubber only on Forehand side and then decide on the backhand. The idea is simple, the lesser number of variables the lesser is the confusion and eventually less adjustments on your part.
Now, what to look for -
1. I personally like to feel the 'bite' on the ball when I topspin. Same ditto with the serves.
2. My push - can I push heavy? Can I push no-spin and can I change the spin on the push in a short to short rally over the table? For reference - if I can do it 5 to 6 times out of 10 then the new setup looks promising.
3. My blocks - do I feel that I can direct the ball anywhere on the table at my will? If yes again with 50-60% accuracy then it is something which can be improved with practice.
4. Now last point - and this is the one which very few people observe. You distance from the table when you change your equipment. This is ingrained within our mind as a muscle memory and it takes time to change this part. For example, if you loop with a faster setup with a reasonable technique your loop should be spinning, lower arc and should land deep. This means that the block will also come deep towards you and might kick more. You need to make adjustments in your playing distance and in your technique on the 5th ball to handle the drive. This is the challenge where most folks find discomfort. As this is a very fine adjustment if you understand what I mean since you need to make it on every ball in the rally and the longer the rally the more is the adjustment.
So, in a nutshell, if I can adjust very quickly then I will adapt and change the setup. I also feel that if you switch between same kind of artificial fibers like out layer ALC to inner layer ALC then the adjustment is mostly on speed. Whereas there are more differences when switching between ALC and ZLC. Same applies for the top layer wood of the blade. Switching from Limba top layer to Koto or Hinoki changes the feel of the ball and thus requires more adjustments. I realized in my game which is more spin oriented is that I personally like a little slower setups which give me more margin for error and compensate for my slow footwork.
That is also perfectly fine (well, maybe not for your wallet 
