T.B., first and foremost, the safety of the tail is great. And do a search on the NOTAR, there has been long discussions on it in the past here.
Performance takes a number of hits due to the tail needing anywhere up to four times the power (factory has admitted up to 210 hp). Taking off and landing in a high/hot enviroment with a NOTAR really shows the lack of performance that it has. Where I am based (2400'), we can not have a NOTAR during the summer unless we run it 600 lbs. under gross. I was flying one last week, and it was temping out at an OAT of only 18c!
The tail has the same authority as a normal tail, it just is not as fast. Can't say the amount of difference, just it is noticable. First time I practiced loss of tail rotor in a hover with it, I thought I could get out and smoke a cigar compared to a regular 500. Now think about that slowness in a mountain canyon with high winds.
Part of this problem is also that the 250-C20R craps out above 2,000' and is no better then the C20B above that altitude (IMHO).
Did you know that an H-3 will decend at a slower rate then a MD600 in an auto!
There are differences in general flying, but any experianced pilot should not have any problem with it.
It is not a fun machine in turbulance or high winds, a lot less stable then a 500E.
If you have an opportunity to fly one, I would say go for it. It is an experiance.
Notar Fan- that is not just a tail issue. It is also a power issue. You run out of power before pedal due to the amount required.