You need to stay 50 nights at Marriott (40 if you're holding HDFC Marriott card) and 60 nights at Accor to reach Platinum. I'm not sure if you can get Accor night credits from credit cards; if you're able to do that, it's even better. If you are in fact traveling for these many nights but dividing the stays between the two, then you're missing out on a lot by not putting everything on a single brand. Even with Accor Platinum, you unlock (2) Suite Night Upgrades, and most importantly lounge access. This can reduce your drinks and dinner cost significantly. And each Suite Night Upgrade can be easily worth ₹20k, even more at resorts.
In a good year, my average is 33-33-33. 33% paid nights, 33% award nights, and 33% bonus nights. Bonus nights include 10 from HDFC Marriott card and the rest from Marriott's Q1 promotion where they give double elite night credits on all paid stays. So to become Platinum in Marriott, you'd need to do 17 paid nights and 17 award nights on average in a calendar year.
I'm able to use points only on half of stays, where I'm getting good redemption value. And quite honestly, I don't mind paying for the remaining stays where I'm not getting redemption deals, considering that these stays don't cost a lot and the earnings rate is very generous. I booked base room without breakfast at Fairfield Agra earlier this year for ₹4.5k a night. Because of my status, I got complimentary breakfast and was upgraded to a suite that costs ₹10k a night, and earned 6.8k points (base + elite bonus + Marriott's promo) in return. All in all, this is a good deal, considering that there are no other hotels in the city willing to give me a suite for ₹4.5k a night. You'll surely find cheaper Accor hotels here as long as you're going for the base room, but one major difference in both is that Accor helps you save money by providing limited benefits, whereas Marriott offers you elevated benefits while keeping the price higher. And I have received so many massive upgrades with Marriott. My reservation in JW Mauritius (base room booked using 47k points a night) was upgraded from ₹80k a night room to a ₹187k a night suite. This is one of the reasons I don't take pricing of both at face value, because once you're done scratching the surface, you'll find a lot of other key differences which makes Marriott far more luxurious, rewarding, and exclusive than Accor.
drsel did mention yesterday that Marriott is overpriced in Mara. Fairmont Mara will cost you what, 60k points on a good night in peak season? JW Mara will easily cost you 120k points a night in the same season. But to really compare JW Mara and Fairmont Mara, you have to see what both these resorts offer. Both are all-inclusive hotels, includes game drives and all. But no one talks about the exclusivity of the resort and game drives. Fairmont has 20 Land Cruisers between 51 rooms, JW has 12 Land Cruisers between 21 rooms, and they have ordered 12 more. Which means starting from sometime next year, JW will have private safari vehicle for all guests, compared to Fairmont where a vehicle is shared between 2-3 rooms if the hotel is running at full capacity. Fairmont Mara does offer private safari, but the cost of that will easily fill the difference between that of two hotels. We were lucky enough to have a private vehicle to ourselves on our last day, so I can tell that there is good difference between shared safari and private safari. You're pretty much free to do whatever you want on private safari, and the guides are very accommodating. A hotel will always cost more when it's offering exclusivity.
