I've owned them both and still have the ETX90 but not because it is the superior scope/mount/tripod. I picked up the 4 SE used at a very low price and eventually sold it in favor of a used C-5 spotter. Later I picked up a used original ETX 90 RA very cheap.. I removed it from the forks and it sits on an alt-az tripod as a spotter.
I would recommend the 4SE over the old ETX or the current model because in my opinion it has the better mount/tripod. The 4/5 SE mount internals more closely resemble the SLT mount than the heavier duty 4/8 SE mount but it performs well enough with the smaller payload. The tripod on the current version appears not to have the almost useless built in jack screw to emulate a wedge. Adequate is about the best you can expect in tripods at these price points, serviceable but best with the legs kept short.
I have not done a side by side comparison with the ETX90 but memory says that the optics were in no way better than the 4 SE. My impression of the current version's tripod and mount are from reviews. My impression of the optics is that they are about the same as on the older versions.
There are things I do not like with both scopes, the flip mirror, the odd sized rear port and the need to buy an adapter for it. The old Also not a defect but the long focal length of a Mak means a small field of view. Depending upon your skies you may find that they are best for the moon and the gas giants, double stars and a few of brighter more compact deep space targets. Both scopes can take a Barlow but I am not clear that you can find a useful focal reducer, though one of the inexpensive .5x reducers screwed into an eyepiece might do the trick.
Both scopes can perform well so I don't want to sound negative. But I think that if you stay with the hobby you will trade up to a larger scope at some point. But if you need portable then both of these kits are on the lighter side.