Have seen a bosch sds-plus drill for 63 quid with 2 chisels and 3 bits. The model is a 2000 RE and the impact force is shown as 1.5 joules. This doesn't seem a lot compared to some of the more expensive models with 2 or 2.5 joules but what does this mean in laymans terms. It is only to replace my hammer drill for general diy and some drilling through to outside walls. Is this adequate or should I be looking for a more powerful model. Thanks