Replaceable stylus and quality of cartridge

Are there very good MM phono cartridges with user-replaceable styli, or do the higher-quality cartridges all come in just one piece, as it were? I'm currently running a Rega P3 with an Elys cart. Been thinking of getting a new 'table and cart -- would want an MM -- and I'd like, all other things being equal, to get a cartridge with a replaceable stylus. But, of course, all other things are seldom equal. In general, are cartridges with replaceable styli of lesser quality than their more-solid brethren?
-- Howard
Yes, there is general agreement that a more rigid one piece system is inherently superior. This in no way means that replaceable stylus cartridges cannot be good, just that they have to make a compromise that non replaceable ones do not. If you want a replaceable stylus one there are many which are quite good, Raul posts lists of them quite often. The new Ortofon line, NOS ones from their old lines, Audio Technica 150 or other model and many others.
I have an Audio Technica AT150MLX. I like it a lot. Although I haven't been able to compare a Rega Exact side-by-side with the AT150MLX, I have heard the Exact in a local show room and then drove home to immediately listen to my rig. Under those not-very-controlled conditions, I come away feeling that the AT150MLX is at least as good as the Exact and a healthy notch up from the Exact. And really, if the Exact was significantly better, the sound of my rig would have left me wanting, but it didn't.

The cartridge body of the AT150MLX is cast or extruded aluminum and is very rigid. The stylus assembly is substantial, rigid, and a very tight fit with the cartridge body. Best of all, the last time I checked, the replacement stylus for the AT150MLX is $179.95.
All of the Ortofon 2M series carts have removable styli.
Dear Howard: The cartridges that already name it here are
very good options ( Johnnyb53 is an expert on that AT 150
MLX that is very good alternative. ), I can add this one:

the cartridge stylus removable design is the normal way to
go on MM/MI cartridge design, 90%-95% of this kind of
cartridges comes with a removable stylus that is an
advantage because not only ( when you need it/stylus needs.
) because you only have to buy the stylus replacement and
change it at your place, with non removable stylus designs
you need to send the cartridge to the manufacturer for make
that stylus change, but because in some cartridge models the
same cartridge body accept different stylus replacement (
normally different stylus shape. ).

If we want to be " purist " I agree with Stanwal,
the non removable stylus cartridges could ( in theory ) have
an advantage on quality performance everything the same.
There are not many MM/MI non removable stylus designs, here
is one of them and it is a great performer, even better that
the Ortofon I linked:

the B&O MMC2 is something to hear/own.

Regards and enjoy the music,