It is worth it and you will see a diffrence.
AMD Phenom II X6 1055T (125W) advantages
In memory-intensive programs, the AMD 1055T processor is 3% faster.
This microprocessor incorporates 3DNow! technology. Even though the 3DNow! instructions may enhance performance of some old games, they are now obsolete, and they are not utilized by modern applications.
Intel Core i5-4590 advantages
In single-threaded programs, the Intel i5-4590 is 77% faster.
Multi-threaded performance of the Intel i5-4590 CPU is better.
The i5-4590 features SSSE3, SSE4.1 and SSE4.2 instructions.
The Intel i5-4590 has Advanced Encryption Standard (AES) technology. These instructions accelerate AES encryption and decryption, and are beneficial if you run applications, that protect your disk or network data.
The microprocessor includes AVX, AVX2, F16C and FMA3 instructions, that were introduced in the recent past. These extensions are not extensively used by programs yet, but their support should improve in future applications.
The processor features on-chip HD 4600 GPU. This graphics unit replaces low-end graphics card, and thus lowers the cost of the system.
Power consumption of the Core i5-4590 microprocessor is lower.
Intel actively supports Socket 1150, used by the i5-4590 CPU, and is going to introduce new processors for the socket in the future.