Upper_Krust
Legend
HI seasong mate! 
Appreciate the love dude.
It might be prudent to include ability score bonuses in the make up of any ECL.
Well if we were to add your above ability scores to the ECL then round down we would be left with ECL 5.

seasong said:This is an alt.rakshasa, designed for use as a mortal/humanoid race with magic in their blood, rather than a strange and evil spirit creature from the outer planes. I'm working on a D&D setting, and Upper Krust's system is turning out to be invaluable in that - this rakshasa will eventually be turned into a mid-ECL PC race.
Appreciate the love dude.

seasong said:For right now, it's also intended as a measure of just how far the system can be pushed in terms of character power, and to test rounding one direction or the other. I have some comments added to that effect at the end.
Rakshasa
Elegant and charismatic, rakshasa are a race of shapeshifting, sentient tigers. Although there is some tendency to viciousness, most tales of their tendency to cruelty are merest prejudices, inspired by primitive fear of efficient predators. Just ask any rakshasa. Socially, they tend to be advisors and performers rather than leaders, and operate with maximum flair and pomp.
Medium Humanoid (Rakshasa)
Ability Scores: STR +2, DEX +4, CON +2, INT +2, WIS +2, CHA +6
It might be prudent to include ability score bonuses in the make up of any ECL.
seasong said:Without Upper Krust's system, I would have placed this one somewhere between ECL +4 and +5.
Rak 4/sor 1 .vs. sor 5 = Rakshasa wins by a good margin
Rak 5/sor 1 .vs. sor 6 or ftr 1/sor 5 = non-Rakshasa wins
The question becomes: as a DM, do you care if there are optimal choices in your campaign? If you prefer there not be, go with ECL +5; if you don't mind munchkin characters, the rakshasa works better at ECL +4... and if you allow race levelling (per Savage Species), the sorcerer who ISN'T a rakshasa probably wasn't paying attention.
So, regarding rounding... I think that for core D&D, which doesn't sweat the small stuff so much, rounding down is probably the best solution for this particular race. It would certainly work best that way in the setting I'm building it for!
By the same token, however, at ECL +4, the rakshasa is an out-and-out better sorcerer than any human or elf at equivalent level, and I don't care what level you run that against. A human sor-20 versus a rakshasa sor-16 is not as good. Some DMs are uncomfortable with that, so while you might default to rounding down, a paragraph explaining the reasoning and/or other options for stingier campaigns, would likely not be out of place.
And at 4.96, the system very neatly nailed my thoughts on the creature. Which goes to show that when I'm designing something as a DM, the system works beautifully; it's only when I start looking for break points as a player that it starts to grind (either over or under-estimating CR).
Well if we were to add your above ability scores to the ECL then round down we would be left with ECL 5.