Vandersteen 3a sigs/ 2wq vs. 5a or 5

I currently have a pair of 2wq's with the model 5 crossover and am considering buying a pair of 3a signatures. I have heard this is 80% or even 90% of the performance of the model 5a's. I am a little skeptical of that though given the cost. Can someone who has compared these setups give me your impressions. Is it close or not, and what are the sonic differences. Thank you for your input.