The sensitivity is very good on all bands. The main difference between it and the RF-2200 is that it is a single conversion set, so birdies show up on the shortwave bands. It has been a while since I gave it a thorough test, but here is what I had to say about its performance back in 2012:
Now let's talk about its performance. On FM, I compared it to my RF-2900 and my stellar FM performing Grundig Satellit 2400. It beats the RF-2900 hands down and gives the Satellit 2400 a run for its money. In terms of just raw sensitivity, it may be a tad more sensitive than the Grundig, but its not quite as selective and actually suffers from mild front-end overload even just on the whip, mostly from 2 local stations. It may be too sensitive for its own good if used in an urban environment. Out in the middle of nowhere, it may be the most sensitive portable you could ever get your hands on.
On AM, Hugo previously reviewed the RF-1180 and claimed it was more sensitive than the famous RF-2200. Another reader claimed the RF-1170 was more sensitive than the GE Superradios. While I haven't done extensive testing, I can fairly confidently confirm that my RF-1188 is in the same ballpark as the RF-1170 and RF-1180 - it is HOT across the entire AM spectrum. The gyro antenna is very directional (even more directional than my Terk AM advantage) and the wide/narrow bandwidth switch is very effective at reducing adjacent interference in narrow mode and improving fidelity in wide. Its probably the most sensitive AM radio I own when using just the internal antenna (My Satellit 2400 is extremely sensitive, but my testing on that radio was done with the help of the Terk antenna).
Shortwave performance is excellent as well. It was hard to do a direct comparison to my other radios since it does not have a digital display, but when I was able to locate and compare weak stations, the RF-1188 held its own. On SSB, this is the best performing of my analog sets - SSB communications were stable and intelligible. The fine-tuning knob comes in handy for tuning in SSB.
In conclusion, the RF-1188 is a stellar performer across the board, and while I have never owned an RF-2200, I suspect it meets or beats the RF-2200 in raw performance and probably sounds better too thanks to its larger speaker. Its a definite keeper and is probably the most "fun" to use radio I currently own.