Very dynamic field. Deal alot with Critical care issues, electrolyte/metabolic problems/renal/endocrine issues related to underlying cancer/neoplasm or adverse effects of chemotherapeutics. Outlook is different as you are trying to prolong life in many many instances rather that looking for a complete cure. oncologists seem to develop their niche: lymphoma/leukemia/blood disorders vs. solid tumors.
In my opinion to be good at haem-onc you need:
1. to be person who pays great attention to fine details and numbers...expect the unexpected.
2. quicking thinking and able to respond to and deal well with critical care issues when dealing with inpatient haem/onc
3. have the ability to display compassion and empathy yet the ability to distance yourself when you are away from work.
4. the advancements in oncology in the past 10-20 years are astounding...i would expect major steps in the next 20 years. if you are interested in a dynamic field...this is it.
this is just my opinion after my haem onc inpatient rotation last month. the best way to get an idea is to work in the field. you'll know what feels right.