Group training is an economical way to get fitness instruction. You won’t get the individual needs analysis and attention as you would expect of a one-on-one session with a personal trainer. But depending on the size of the group, you should still get some individual attention.
The smaller the group size, the more likely it is that you will get individual attention. Paradoxically, a smaller group size may also be more friendly. This is because you are probably more likely to be interacting with each other.
One significant benefit of group training is the social aspect and the additional motivation that can bring. So although group training won’t be optimal for your specific physical needs. If it fits your budget and you need the social aspect to motivate you, then make sure you choose a good operator.