I did Bangalore - Mangalore on 31st October and returned to Bangalore just yesterday afternoon. Good news is that I had a good time and diwali celebrations in Mangalore and bad news is that on my way back to Bangalore yesterday bent 3 steel rims of my tyres due to my car hitting huge potholes at high speeds. This happened between Hassan and CR patna. I could not capture the photos on my way back as i had to cover the distance ASAP since had to meet someone urgently in Bangalore. However, for benefit of everyone and for guys who are driving soon would like to post pics of road conditions (these pics were captured when i was driving from Bangalore to Mangalore).
Both ways i opted for Magadi Road - Magadi - NH48 - Kunigal - CR patna - Hassan - Belur - Gendehalli - Mudigere- Kottigehara - Charmadi - Ujire - Belthangady - BC Road - Mangalore route.
Started from my Basaveshwaranagar residence at 5:30 AM (wanted to start early ~4:30 AM but when you are traveling with family especially ladies i dont have to elaborate more the reason for delay

)
Magadi town is as usual without any change since i last traveled in September 2010. When will the authorities wake up - Though the pic captured was not the worst stretch. There are more worst stretches (with non-existing roads

) around Magadi town which was missed to capture
Apart from 2-3 kms stretch around Magadi town entire stretch from Magadi town until you hit NH 48 is a breeze. One can maintain an average speed of 100 kms/hour easily.
The stretch on NH48 after Kunigal to Hassan via CR patna is very tricky since you have blend of superb roads as well as mighty potholes enough to severly damage your steel rims/alloys if you are not careful. you will get smooth roads up to a stretch of 5-6 kms and then suddenly an unexpected potholes out of nowhere and difficult to avoid if you are on high speeds. This is the stretch where i bent my 3 steel rims (my mistake though - i could have avoided this if i was not ripping at 120 + kms per/hour). No point regretting. Sorry could not capture the pics on this stretch wanted to do it when i was returning but due to damage of rims i was irritated the reminder of journey.
Hassan to Belur (as usual the best stretch to enjoy driving and I am happy they have maintained this stretch extremely well). One can easily maintain average speed of 120 kms/hour since the traffic is also low to least. But watch out for sharp curves and divider on the way since i saw a tempo traveler not noticing the divider and ramming it badly on the way. when you are at high speeds and maneuvering on sharp curves very easy to miss divider and lose control. Overall this was the best stretch to drive on the entire route.
From Belur to Mudigere via Gendehalli there is no change in road conditions - as usual narrow road but less traffic with occasional potholes but as you are approaching Mudigere town you will find around 2 kms stretch before Mudigere town as bad as Magadi town full of potholes and non-existing roads (Sorry missed to capture pics of this stretch).
From Mudigere to Kottigehara roads are good but very difficult to speed on this stretch due to sharp curves and narrow road (May be i could not speed since mine is tallboy and very difficult to control the vehicle at steep/sharp curves when you are speeding) See below the pic of this stretch:
I hit Charmadi ghat ~ 11 AM and it was not as beautiful and scenic when i was there in september - No fog and clear visibility. Charmadi Ghat is good except for last 11-12 kms stretch with non-existing roads especially at hairpin bends - One should be careful to make sure that you are driving dead slow on those hairpin bends since if your tyres are old very easy to skid from there and lose control.
Also I remember someone mentioning about leeches in water fall. This time I wanted to re-confirm that there are no leeches since many tourists ventured in to the water happily bathing.
Disclaimer: Venture at your own risk since i myself didn't experience and comments were based on my observation.
From Belthangady to BC Road – I wanted to take other route which diverts from Ujire and joins Uppinangady as suggested few days back by _chikku on this thread but preferred not to experiment with routes for this time. The stretch after Belthangady has detoriated more than since I last traveled during September. Many places you can find bad potholes/non-existing roads and maximum speed you can drive is not more than 40 km/hour.
when i was driving back to Bangalore (started around 5 AM from Mangalore) from BC road to Belthangady stretch it was foggy and poor visibility. I was expecting fog on Charmadi ghat. Luckily no fog on charmadi when returning back as well. I hit charmadi ghat ~7:30 AM on the way back (Sorry again no pics on this stretch)