Izula and RC-3 are both excellent - I think an RC-3 may feel more substantial in-hand because of the heft and slightly larger size. If you compare an RC3 and non-scaled Izula the difference will be more dramatic.
That said, you can't go wrong with either, you may come to want both anyway, and if you get one and it's not quite what you wanted, there are tons of people (some on this forum) that would eagerly take it off your hands.
I started off looking for a larger ~5" blade bush/survival knife - I was down to the Gerber LMFII ASEK and the SOG SEAL PUP. I went with the Gerber. As soon as it arrived I was disappointed - the knife ended up getting returned & refunded for a material defect and I had to pick another knife (Amazon refunded, not Gerber). Now I was considering the Fallkniven line - then I came across ESEE knives. The thought of getting a Tom Brown Tracker crossed my mind, but with people SO polarized on this design, I didn't want to gamble on being on the losing end of that spectrum. After reviewing this forum a bit, looking at a BUNCH of review videos on YouTube, and reading the warranty policy, the decision was easy for me.
ESEE knives rocks - the product (ROWEN), the company, and their support of their goods and the outdoor enthusiast/military/LEO/survival communities at-large.
RC-5 was the right size for my needs.
Got the knife and have been happier with it than I anticipated - it exceeded my expectations, and the community of owners has been very helpful, supportive and encouraging... albeit a bit zealous sometimes... I'm surprised there isn't an ESEE Knives Tatoo thread yet (this is NOT a dare, people!)