You will hear different opinions on this, and as usual you should try both and go with what works for you.
I recently worked through the same decision, and incase you find it helpful, I will offer my experience and findings.
For my anaconda, I had engineered (Enhanced, I think) 7A shields, and every utility slot filled with engineered shield cell boosters. My objective was to build up the highest MJ that I could. The majority of my optional internal slots were filled with hull reinforcement modules. I had tanked hull and shields.
I could fare well against NPCs for the most part, but I quickly realized that the time required to recharge my shields was a big problem. Once my shields were nearly gone, it would take something like 18 minutes to recharge. I had read about shield cell banks, but thoses were completely ineffective as they couldn't restore a significant percentage of the shield. Effectively my shields didn't recharge, which means they were really no different than armor.
On the advice of someone in these forums, I slapped on a bi-weave but NOT in the class 7 slot. I put the biweave in the class 6 slot, and a 7B Shield Cell Bank in the class 7 slot, a 6B SCB in the other class 6 slot, and a 5B in one of the class 5 slots.
The 7B shield cell banks restore less MJ per cell bank than the 7A, but the 7B has one more cell bank than the 7A. So the total MJ that the 7B module can restore is higher than the 7A module.
The raw MJ of the 6C Biweave is less than the 7A, but the MJ of damage that can be absorbed by the 6C biweave plus the cell banks is far, far, greater than the 7A plus five or six cell boosters. Also, your shields will recharge quite a bit in between battles without using the cell banks.
I finally know the experince of sitting in the middle of four or five hostile NPCs and laughing. No longer do I need to leave the battle or RES to return to the station to recharge my shields. I can't say enough about the difference, and I have seen the same results on my FDL, and as a general rule, I now fill the second highest slot with a biweave and the highest with a cell bank for any ship that I expect will see combat.
Once I get back to my laptop I will post the coriolis links to my ship with and without the biweaves so you can see for yourself.
I will say that should you go this route, that you shoud practice using your cell banks before you get into combat. You will need heat sinks, and plan on firing two cell banks per heat sink (I fire a cell bank and launch a heat sink when my heat hits 80% or so, then fire the other cell bank). If you run out of heat sinks, I'm not sure that you can safely use a cell bank.