All of the posts above are top quality and worth understanding.
I will try to explain why a blade that is all wood and between All+ and Off- speed rating is generally best for when someone that level wants to have a racket that will help the development of their game the most.
An all wood blade gives you more dwell time and feeling. It helps you feel the ball when the ball is on the racket. The feedback that you get from that is different than the kind of feedback you get from a carbon blade. The feedback from an all wood blade actually helps you adjust your contact, over time, so that the contact improves and your shot quality gets better. This happens on a sub-cortical level. That means you are not even conscious of it happening. This is because good contact actually feels good and bad contact does not. So your body learns to make that contact that feels better faster.
With a blade with carbon, the carbon actually helps make a ball that is not contacted as well feel better and you get better shot than you should from a ball that is not really contacted well. However, that "enlarged sweetspot" effect that a carbon blade gives you making it possible to mess up more and get away with it, slows down your improvement because it causes you to develop and improve your contact for spin much more slowly.
The extra control, the extra dwell time from an all wood blade that is not too fast: they help your strokes get better faster. They help you learn how to spin the ball more.
With a carbon blade you are much more likely to continue hitting the ball too directly and not getting enough spin on the ball. At a level under 2000-2100 one of the most important things is learning how to spin the ball well so your strokes have power and accuracy.
The slower blade also can help give you the incentive to learn how to get your body into your stroke more fully. A carbon blade does so much to give your ball more pace that you don't learn how to generate as much power from your body mechanics during your stroke. So it will take longer to get your strokes to a higher level.
If you can generate good pace with an All+ or Off- blade while looping the ball with good spin, you are probably doing a lot right. It would be well worth your development to have a moderate speed all wood blade with top flight rubbers on it.
Blades to consider would be:
Nexy Peter Pan
Tibhar Kim Jung Hoon
Tibhar Stratus Power Wood
Stiga Allround Evolution
Yasaka Sweden Extra
Butterfly Primorac Off-
If you wanted to go fancier and more expensive:
OSP Virtuoso (Off-)
OSP Virtuoso+
Nittaku Acoustic
Any of those blades would be really good for developing and improving your technique.
But in the end, whatever you wind up using, focus on technique first.
