I use a 4 channel avionixx 800.4, which is rated at 125x4 at 4 ohm. I also have the sub running off the rear channels bridged. So in all reality I don't think the front channels are capable of more than 50-75 watts continuous power into 4 ohm.
Now Imho my car sounds pretty dynamic and I have no problem bottoming out my mids quite easily. Others have reported significantly improved results when using higher powered amps.
My guess is that it's just a matter of tuning. I always like to recommend more power than needed, since that's the easiest solution for most people than to try to walk them through tuning their car online.
I mean... I also don't lowpass my sub and I think I have almost as good as you can get transparency and integration with the mid/bass... yet you will see people who swear that their sub has to be crossed at 60hz 100db slope to get it to dissappear.