Sony PS-LX5: Upgrading stock XL-200?

Hi there! This is my first post in this forum. After years in the digital domain, tweaking and becoming frustrated, I felt in some way deceived and moved to the absolute new for me field of turntables.

My first approach was a Dual 1257 with a Dual (Ortofon) 45S ultra-low mass cartridge with spherical stylus. Not being happy with the sound I upgraded it by replacing the cartridge by a Ortofon ULM 55E with elliptical stylus and tonearm rewiring with litz cable. Absolute noticeable quality improvement after the upgrade but still not happy: sound tends to be quite v-shaped with great emphasis in lows and specially highs. Not what  I'm looking for, that is a neutral sound in the source (than can be tuned, if necessary, in next stages).

Then someone gave me a Sony PS-LX5. Supposed to be a turntable addressed to the medium market segment, it took my attention because it was launched to the market the year before the launching of the CD, then being the result of years of development with good engineering behind it (quartz controlled speed direct drive, anti resonant chassis, ultra low mass). The turntable came with a Sony XL200 headshell+cartridge but with no stylus. This turntable had the option of replacing the XL200 by a Sony SH-151 headshell then opening the door to mount conventional cartridges between 2,2 to 6,5 grams. Luckily I catched one of them on Ebay days ago by 40 euro including shipping.

So now I have the option of installing a new stylus for the XL-200 or moving to a brand new cartridge, and to be honest I don't know how to proceed. First option offers two sub-options actually, since spherical or elliptical stylus can be mounted with prices ranging from 15 to 45 euro including shipping. So I would like to get your advice about these questions: Staying with the XL-200 and installing a spherical stylus? or elliptical stylus? or moving to a brand new cartridge between 2,2 and 6,5 grams? and in this case what cartridge in terms of neutrality, sound quality and pricing (in that order)?

Thanks in advance.