Im going to have to disagree with you davereo. I didnt notice any erosion of handling skills after a winter on the trainer and I might add, a LOT of trainer time. As a result I got MUCH more comfortable spending time in the drops, which I did not do prior. Then when I got my aero bars I used trainer time to get used to them, get them adjusted, etc. As a result of that, I have gotten much more comfortable in and using the aero bars and holding the bike steady when using them.
In fact, I get so comfortable in them I usually gear down to a smaller cog because I tend to be able to pedal easier in the aero bars than I do on the hoods. In fact, it has come that when the road is flat enough and I want to conserve energy for longer rides I will get down on the aero bar because I can hold a much more consistent pace and as mentioned it seems a bit easier to pedal there
I will also add that the trainer helped me tremendously with regards to just overall performance on the bike and it allows me to work/target specific weaknesses with Trainer Road.
Now I realize to each his/her own and not everyone is the same and results will vary. But for me, personally, I love the trainer. Not as much as riding on the road, but I love riding on the trainer when the weather outside is not good. In fact, this winter, really want to get on the thing and do a half century and work my way up to a full century like that whackoo xela. Though, in all fairness, he has rollers, and I dont.