Is the Honda CRF 230L a good bike?

The Honda is a good machine (but, so is your Yamaha). Those two bikes are basically so alike its no wonder that you were disappointed, especially if you were looking for more power. If you like that style bike (IE single cylinder 4 stroke on-off road) you are going to have to look into the 400cc range for significant power increase. Or go for a bigger one, there are plenty of used KLR 650s, XL 650s, and DR 650s out there for reasonable prices.