Rwenzori or Mount Kenya?
Both mountains ask for more than walking to reach the top, which makes this a closer comparison than either gets against Kilimanjaro. If you are weighing the Rwenzori against Mount Kenya specifically, here is where the two genuinely differ.
Altitude
Mount Kenya's highest point, Batian, is commonly cited at around 5,199 metres, though it requires technical rock climbing rather than a trekking route — the summit most trekkers actually reach, Point Lenana, sits lower, at roughly 4,985 metres, and is accessible without technical climbing. Margherita Peak, the Rwenzori's high point, is 5,109 metres and does require glacier travel with rope and crampons.
Technical difficulty
This is the genuine point of comparison. Point Lenana, Mount Kenya's trekking summit, needs no technical skill. Margherita does — the final section is a glacier crossing requiring rope and crampons. If a non-technical summit at serious altitude is the goal, Mount Kenya's Point Lenana is the more directly comparable objective; if you specifically want the technical element, Margherita is the closer match to Kenya's true summit, Batian, which itself requires rock climbing rather than glacier travel.
Weather
Both mountains sit near the equator and both see significant rainfall, though — a proper seasonal comparison between the two is still being compiled rather than asserted from general impression.
Access and cost
Mount Kenya benefits from a larger, more established trekking industry than the Rwenzori, with correspondingly more route and operator choice. Both countries revised their park fee structures recently, so any figure quoted online may be out of date. We will give you a current Rwenzori cost when you enquire; check Mount Kenya's directly with a Kenyan operator rather than relying on a comparison table.
Which to choose
If you want a non-technical summit at real altitude with strong existing infrastructure, Mount Kenya's Point Lenana route is the easier recommendation. If you want fewer people, more unusual high-altitude vegetation, and are prepared for genuinely wet, broken terrain over the walk-in, the Rwenzori is the more distinctive trip — and if the summit itself needs to be technical, the Rwenzori's Margherita Peak is the more accessible technical objective of the two, given Mount Kenya's true summit requires rock climbing rather than glacier work.